
<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta charset="utf-8" />
    <title>importlib — The implementation of import &#8212; Python 3.8.13 documentation</title><meta name="viewport" content="width=device-width, initial-scale=1.0">
    
    <link rel="stylesheet" href="../_static/pydoctheme.css?2022.1" type="text/css" />
    <link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
    
    <script id="documentation_options" data-url_root="../" src="../_static/documentation_options.js"></script>
    <script src="../_static/jquery.js"></script>
    <script src="../_static/underscore.js"></script>
    <script src="../_static/doctools.js"></script>
    <script src="../_static/language_data.js"></script>
    
    <script src="../_static/sidebar.js"></script>
    
    <link rel="search" type="application/opensearchdescription+xml"
          title="Search within Python 3.8.13 documentation"
          href="../_static/opensearch.xml"/>
    <link rel="author" title="About these documents" href="../about.html" />
    <link rel="index" title="Index" href="../genindex.html" />
    <link rel="search" title="Search" href="../search.html" />
    <link rel="copyright" title="Copyright" href="../copyright.html" />
    <link rel="next" title="Using importlib.metadata" href="importlib.metadata.html" />
    <link rel="prev" title="runpy — Locating and executing Python modules" href="runpy.html" />
    <link rel="canonical" href="https://docs.python.org/3/library/importlib.html" />
    
      
    

    
    <style>
      @media only screen {
        table.full-width-table {
            width: 100%;
        }
      }
    </style>
<link rel="shortcut icon" type="image/png" href="../_static/py.svg" />
            <script type="text/javascript" src="../_static/copybutton.js"></script>
            <script type="text/javascript" src="../_static/menu.js"></script> 

  </head>
<body>
<div class="mobile-nav">
    <input type="checkbox" id="menuToggler" class="toggler__input" aria-controls="navigation"
           aria-pressed="false" aria-expanded="false" role="button" aria-label="Menu" />
    <label for="menuToggler" class="toggler__label">
        <span></span>
    </label>
    <nav class="nav-content" role="navigation">
         <a href="https://www.python.org/" class="nav-logo">
             <img src="../_static/py.svg" alt="Logo"/>
         </a>
        <div class="version_switcher_placeholder"></div>
        <form role="search" class="search" action="../search.html" method="get">
            <svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" class="search-icon">
                <path fill-rule="nonzero"
                        d="M15.5 14h-.79l-.28-.27a6.5 6.5 0 001.48-5.34c-.47-2.78-2.79-5-5.59-5.34a6.505 6.505 0 00-7.27 7.27c.34 2.8 2.56 5.12 5.34 5.59a6.5 6.5 0 005.34-1.48l.27.28v.79l4.25 4.25c.41.41 1.08.41 1.49 0 .41-.41.41-1.08 0-1.49L15.5 14zm-6 0C7.01 14 5 11.99 5 9.5S7.01 5 9.5 5 14 7.01 14 9.5 11.99 14 9.5 14z" fill="#444"></path>
            </svg>
            <input type="text" name="q" aria-label="Quick search"/>
            <input type="submit" value="Go"/>
        </form>
    </nav>
    <div class="menu-wrapper">
        <nav class="menu" role="navigation" aria-label="main navigation">
            <div class="language_switcher_placeholder"></div>
  <h3><a href="../contents.html">Table of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib</span></code> — The implementation of <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a><ul>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#functions">Functions</a></li>
<li><a class="reference internal" href="#module-importlib.abc"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.abc</span></code> – Abstract base classes related to import</a></li>
<li><a class="reference internal" href="#module-importlib.resources"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.resources</span></code> – Resources</a></li>
<li><a class="reference internal" href="#module-importlib.machinery"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.machinery</span></code> – Importers and path hooks</a></li>
<li><a class="reference internal" href="#module-importlib.util"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.util</span></code> – Utility code for importers</a></li>
<li><a class="reference internal" href="#examples">Examples</a><ul>
<li><a class="reference internal" href="#importing-programmatically">Importing programmatically</a></li>
<li><a class="reference internal" href="#checking-if-a-module-can-be-imported">Checking if a module can be imported</a></li>
<li><a class="reference internal" href="#importing-a-source-file-directly">Importing a source file directly</a></li>
<li><a class="reference internal" href="#setting-up-an-importer">Setting up an importer</a></li>
<li><a class="reference internal" href="#approximating-importlib-import-module">Approximating <code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.import_module()</span></code></a></li>
</ul>
</li>
</ul>
</li>
</ul>

  <h4>Previous topic</h4>
  <p class="topless"><a href="runpy.html"
                        title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">runpy</span></code> — Locating and executing Python modules</a></p>
  <h4>Next topic</h4>
  <p class="topless"><a href="importlib.metadata.html"
                        title="next chapter">Using <code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.metadata</span></code></a></p>
  <div role="note" aria-label="source link">
    <h3>This Page</h3>
    <ul class="this-page-menu">
      <li><a href="../bugs.html">Report a Bug</a></li>
      <li>
        <a href="https://github.com/python/cpython/blob/3.8/Doc/library/importlib.rst"
            rel="nofollow">Show Source
        </a>
      </li>
    </ul>
  </div>
        </nav>
    </div>
</div>

  
    <div class="related" role="navigation" aria-label="related navigation">
      <h3>Navigation</h3>
      <ul>
        <li class="right" style="margin-right: 10px">
          <a href="../genindex.html" title="General Index"
             accesskey="I">index</a></li>
        <li class="right" >
          <a href="../py-modindex.html" title="Python Module Index"
             >modules</a> |</li>
        <li class="right" >
          <a href="importlib.metadata.html" title="Using importlib.metadata"
             accesskey="N">next</a> |</li>
        <li class="right" >
          <a href="runpy.html" title="runpy — Locating and executing Python modules"
             accesskey="P">previous</a> |</li>

          <li><img src="../_static/py.svg" alt="python logo" style="vertical-align: middle; margin-top: -1px"/></li>
          <li><a href="https://www.python.org/">Python</a> &#187;</li>
          <li class="switchers">
            <div class="language_switcher_placeholder"></div>
            <div class="version_switcher_placeholder"></div>
          </li>
          <li>
              
          </li>
    <li id="cpython-language-and-version">
      <a href="../index.html">3.8.13 Documentation</a> &#187;
    </li>

          <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="modules.html" accesskey="U">Importing Modules</a> &#187;</li>
                <li class="right">
                    

    <div class="inline-search" role="search">
        <form class="inline-search" action="../search.html" method="get">
          <input placeholder="Quick search" aria-label="Quick search" type="text" name="q" />
          <input type="submit" value="Go" />
          <input type="hidden" name="check_keywords" value="yes" />
          <input type="hidden" name="area" value="default" />
        </form>
    </div>
                     |
                </li>
            
      </ul>
    </div>    

    <div class="document">
      <div class="documentwrapper">
        <div class="bodywrapper">
          <div class="body" role="main">
            
  <div class="section" id="module-importlib">
<span id="importlib-the-implementation-of-import"></span><h1><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib</span></code> — The implementation of <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code><a class="headerlink" href="#module-importlib" title="Permalink to this headline">¶</a></h1>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.1.</span></p>
</div>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.8/Lib/importlib/__init__.py">Lib/importlib/__init__.py</a></p>
<hr class="docutils" />
<div class="section" id="introduction">
<h2>Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
<p>The purpose of the <a class="reference internal" href="#module-importlib" title="importlib: The implementation of the import machinery."><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib</span></code></a> package is two-fold. One is to provide the
implementation of the <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a> statement (and thus, by extension, the
<a class="reference internal" href="functions.html#__import__" title="__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">__import__()</span></code></a> function) in Python source code. This provides an
implementation of <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code> which is portable to any Python
interpreter. This also provides an implementation which is easier to
comprehend than one implemented in a programming language other than Python.</p>
<p>Two, the components to implement <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a> are exposed in this
package, making it easier for users to create their own custom objects (known
generically as an <a class="reference internal" href="../glossary.html#term-importer"><span class="xref std std-term">importer</span></a>) to participate in the import process.</p>
<div class="admonition seealso">
<p class="admonition-title">See also</p>
<dl class="simple">
<dt><a class="reference internal" href="../reference/simple_stmts.html#import"><span class="std std-ref">The import statement</span></a></dt><dd><p>The language reference for the <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a> statement.</p>
</dd>
<dt><a class="reference external" href="https://www.python.org/doc/essays/packages/">Packages specification</a></dt><dd><p>Original specification of packages. Some semantics have changed since
the writing of this document (e.g. redirecting based on <code class="docutils literal notranslate"><span class="pre">None</span></code>
in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>).</p>
</dd>
<dt>The <a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">__import__()</span></code></a> function</dt><dd><p>The <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a> statement is syntactic sugar for this function.</p>
</dd>
<dt><span class="target" id="index-0"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0235"><strong>PEP 235</strong></a></dt><dd><p>Import on Case-Insensitive Platforms</p>
</dd>
<dt><span class="target" id="index-1"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0263"><strong>PEP 263</strong></a></dt><dd><p>Defining Python Source Code Encodings</p>
</dd>
<dt><span class="target" id="index-2"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a></dt><dd><p>New Import Hooks</p>
</dd>
<dt><span class="target" id="index-3"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0328"><strong>PEP 328</strong></a></dt><dd><p>Imports: Multi-Line and Absolute/Relative</p>
</dd>
<dt><span class="target" id="index-4"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0366"><strong>PEP 366</strong></a></dt><dd><p>Main module explicit relative imports</p>
</dd>
<dt><span class="target" id="index-5"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0420"><strong>PEP 420</strong></a></dt><dd><p>Implicit namespace packages</p>
</dd>
<dt><span class="target" id="index-6"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0451"><strong>PEP 451</strong></a></dt><dd><p>A ModuleSpec Type for the Import System</p>
</dd>
<dt><span class="target" id="index-7"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0488"><strong>PEP 488</strong></a></dt><dd><p>Elimination of PYO files</p>
</dd>
<dt><span class="target" id="index-8"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0489"><strong>PEP 489</strong></a></dt><dd><p>Multi-phase extension module initialization</p>
</dd>
<dt><span class="target" id="index-9"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0552"><strong>PEP 552</strong></a></dt><dd><p>Deterministic pycs</p>
</dd>
<dt><span class="target" id="index-10"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-3120"><strong>PEP 3120</strong></a></dt><dd><p>Using UTF-8 as the Default Source Encoding</p>
</dd>
<dt><span class="target" id="index-11"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a></dt><dd><p>PYC Repository Directories</p>
</dd>
</dl>
</div>
</div>
<div class="section" id="functions">
<h2>Functions<a class="headerlink" href="#functions" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="importlib.__import__">
<code class="sig-prename descclassname">importlib.</code><code class="sig-name descname">__import__</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">globals=None</em>, <em class="sig-param">locals=None</em>, <em class="sig-param">fromlist=()</em>, <em class="sig-param">level=0</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.__import__" title="Permalink to this definition">¶</a></dt>
<dd><p>An implementation of the built-in <a class="reference internal" href="functions.html#__import__" title="__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">__import__()</span></code></a> function.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Programmatic importing of modules should use <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">import_module()</span></code></a>
instead of this function.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.import_module">
<code class="sig-prename descclassname">importlib.</code><code class="sig-name descname">import_module</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">package=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.import_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Import a module. The <em>name</em> argument specifies what module to
import in absolute or relative terms
(e.g. either <code class="docutils literal notranslate"><span class="pre">pkg.mod</span></code> or <code class="docutils literal notranslate"><span class="pre">..mod</span></code>). If the name is
specified in relative terms, then the <em>package</em> argument must be set to
the name of the package which is to act as the anchor for resolving the
package name (e.g. <code class="docutils literal notranslate"><span class="pre">import_module('..mod',</span> <span class="pre">'pkg.subpkg')</span></code> will import
<code class="docutils literal notranslate"><span class="pre">pkg.mod</span></code>).</p>
<p>The <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">import_module()</span></code></a> function acts as a simplifying wrapper around
<a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.__import__()</span></code></a>. This means all semantics of the function are
derived from <a class="reference internal" href="#importlib.__import__" title="importlib.__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.__import__()</span></code></a>. The most important difference
between these two functions is that <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">import_module()</span></code></a> returns the
specified package or module (e.g. <code class="docutils literal notranslate"><span class="pre">pkg.mod</span></code>), while <a class="reference internal" href="functions.html#__import__" title="__import__"><code class="xref py py-func docutils literal notranslate"><span class="pre">__import__()</span></code></a>
returns the top-level package or module (e.g. <code class="docutils literal notranslate"><span class="pre">pkg</span></code>).</p>
<p>If you are dynamically importing a module that was created since the
interpreter began execution (e.g., created a Python source file), you may
need to call <a class="reference internal" href="#importlib.invalidate_caches" title="importlib.invalidate_caches"><code class="xref py py-func docutils literal notranslate"><span class="pre">invalidate_caches()</span></code></a> in order for the new module to be
noticed by the import system.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.3: </span>Parent packages are automatically imported.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.find_loader">
<code class="sig-prename descclassname">importlib.</code><code class="sig-name descname">find_loader</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">path=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.find_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>Find the loader for a module, optionally within the specified <em>path</em>. If the
module is in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.modules</span></code></a>, then <code class="docutils literal notranslate"><span class="pre">sys.modules[name].__loader__</span></code> is
returned (unless the loader would be <code class="docutils literal notranslate"><span class="pre">None</span></code> or is not set, in which case
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised). Otherwise a search using <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a>
is done. <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned if no loader is found.</p>
<p>A dotted name does not have its parents implicitly imported as that requires
loading them and that may not be desired. To properly import a submodule you
will need to import all parent packages of the submodule and use the correct
argument to <em>path</em>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>If <code class="docutils literal notranslate"><span class="pre">__loader__</span></code> is not set, raise <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a>, just like when the
attribute is set to <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.util.find_spec" title="importlib.util.find_spec"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.find_spec()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.invalidate_caches">
<code class="sig-prename descclassname">importlib.</code><code class="sig-name descname">invalidate_caches</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.invalidate_caches" title="Permalink to this definition">¶</a></dt>
<dd><p>Invalidate the internal caches of finders stored at
<a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a>. If a finder implements <code class="docutils literal notranslate"><span class="pre">invalidate_caches()</span></code> then it
will be called to perform the invalidation.  This function should be called
if any modules are created/installed while your program is running to
guarantee all finders will notice the new module’s existence.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.reload">
<code class="sig-prename descclassname">importlib.</code><code class="sig-name descname">reload</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.reload" title="Permalink to this definition">¶</a></dt>
<dd><p>Reload a previously imported <em>module</em>.  The argument must be a module object,
so it must have been successfully imported before.  This is useful if you
have edited the module source file using an external editor and want to try
out the new version without leaving the Python interpreter.  The return value
is the module object (which can be different if re-importing causes a
different object to be placed in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>).</p>
<p>When <a class="reference internal" href="#importlib.reload" title="importlib.reload"><code class="xref py py-func docutils literal notranslate"><span class="pre">reload()</span></code></a> is executed:</p>
<ul class="simple">
<li><p>Python module’s code is recompiled and the module-level code re-executed,
defining a new set of objects which are bound to names in the module’s
dictionary by reusing the <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> which originally loaded the
module.  The <code class="docutils literal notranslate"><span class="pre">init</span></code> function of extension modules is not called a second
time.</p></li>
<li><p>As with all other objects in Python the old objects are only reclaimed
after their reference counts drop to zero.</p></li>
<li><p>The names in the module namespace are updated to point to any new or
changed objects.</p></li>
<li><p>Other references to the old objects (such as names external to the module) are
not rebound to refer to the new objects and must be updated in each namespace
where they occur if that is desired.</p></li>
</ul>
<p>There are a number of other caveats:</p>
<p>When a module is reloaded, its dictionary (containing the module’s global
variables) is retained.  Redefinitions of names will override the old
definitions, so this is generally not a problem.  If the new version of a
module does not define a name that was defined by the old version, the old
definition remains.  This feature can be used to the module’s advantage if it
maintains a global table or cache of objects — with a <a class="reference internal" href="../reference/compound_stmts.html#try"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">try</span></code></a>
statement it can test for the table’s presence and skip its initialization if
desired:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="k">try</span><span class="p">:</span>
    <span class="n">cache</span>
<span class="k">except</span> <span class="ne">NameError</span><span class="p">:</span>
    <span class="n">cache</span> <span class="o">=</span> <span class="p">{}</span>
</pre></div>
</div>
<p>It is generally not very useful to reload built-in or dynamically loaded
modules.  Reloading <a class="reference internal" href="sys.html#module-sys" title="sys: Access system-specific parameters and functions."><code class="xref py py-mod docutils literal notranslate"><span class="pre">sys</span></code></a>, <a class="reference internal" href="__main__.html#module-__main__" title="__main__: The environment where the top-level script is run."><code class="xref py py-mod docutils literal notranslate"><span class="pre">__main__</span></code></a>, <a class="reference internal" href="builtins.html#module-builtins" title="builtins: The module that provides the built-in namespace."><code class="xref py py-mod docutils literal notranslate"><span class="pre">builtins</span></code></a> and other
key modules is not recommended.  In many cases extension modules are not
designed to be initialized more than once, and may fail in arbitrary ways
when reloaded.</p>
<p>If a module imports objects from another module using <a class="reference internal" href="../reference/simple_stmts.html#from"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">from</span></code></a> …
<a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a> …, calling <a class="reference internal" href="#importlib.reload" title="importlib.reload"><code class="xref py py-func docutils literal notranslate"><span class="pre">reload()</span></code></a> for the other module does not
redefine the objects imported from it — one way around this is to
re-execute the <code class="xref std std-keyword docutils literal notranslate"><span class="pre">from</span></code> statement, another is to use <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code>
and qualified names (<em>module.name</em>) instead.</p>
<p>If a module instantiates instances of a class, reloading the module that
defines the class does not affect the method definitions of the instances —
they continue to use the old class definition.  The same is true for derived
classes.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.7: </span><a class="reference internal" href="exceptions.html#ModuleNotFoundError" title="ModuleNotFoundError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ModuleNotFoundError</span></code></a> is raised when the module being reloaded lacks
a <code class="xref py py-class docutils literal notranslate"><span class="pre">ModuleSpec</span></code>.</p>
</div>
</dd></dl>

</div>
<div class="section" id="module-importlib.abc">
<span id="importlib-abc-abstract-base-classes-related-to-import"></span><h2><a class="reference internal" href="#module-importlib.abc" title="importlib.abc: Abstract base classes related to import"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.abc</span></code></a> – Abstract base classes related to import<a class="headerlink" href="#module-importlib.abc" title="Permalink to this headline">¶</a></h2>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.8/Lib/importlib/abc.py">Lib/importlib/abc.py</a></p>
<hr class="docutils" />
<p>The <a class="reference internal" href="#module-importlib.abc" title="importlib.abc: Abstract base classes related to import"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.abc</span></code></a> module contains all of the core abstract base classes
used by <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a>. Some subclasses of the core abstract base classes
are also provided to help in implementing the core ABCs.</p>
<p>ABC hierarchy:</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="nb">object</span>
 <span class="o">+--</span> <span class="n">Finder</span> <span class="p">(</span><span class="n">deprecated</span><span class="p">)</span>
 <span class="o">|</span>    <span class="o">+--</span> <span class="n">MetaPathFinder</span>
 <span class="o">|</span>    <span class="o">+--</span> <span class="n">PathEntryFinder</span>
 <span class="o">+--</span> <span class="n">Loader</span>
      <span class="o">+--</span> <span class="n">ResourceLoader</span> <span class="o">--------+</span>
      <span class="o">+--</span> <span class="n">InspectLoader</span>          <span class="o">|</span>
           <span class="o">+--</span> <span class="n">ExecutionLoader</span> <span class="o">--+</span>
                                 <span class="o">+--</span> <span class="n">FileLoader</span>
                                 <span class="o">+--</span> <span class="n">SourceLoader</span>
</pre></div>
</div>
<dl class="class">
<dt id="importlib.abc.Finder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">Finder</code><a class="headerlink" href="#importlib.abc.Finder" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-finder"><span class="xref std std-term">finder</span></a>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.3: </span>Use <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">MetaPathFinder</span></code></a> or <a class="reference internal" href="#importlib.abc.PathEntryFinder" title="importlib.abc.PathEntryFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">PathEntryFinder</span></code></a> instead.</p>
</div>
<dl class="method">
<dt id="importlib.abc.Finder.find_module">
<em class="property">abstractmethod </em><code class="sig-name descname">find_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.Finder.find_module" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method for finding a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> for the specified
module.  Originally specified in <span class="target" id="index-12"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a>, this method was meant
for use in <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a> and in the path-based import subsystem.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> when called instead of raising
<a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.MetaPathFinder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">MetaPathFinder</code><a class="headerlink" href="#importlib.abc.MetaPathFinder" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-meta-path-finder"><span class="xref std std-term">meta path finder</span></a>. For
compatibility, this is a subclass of <a class="reference internal" href="#importlib.abc.Finder" title="importlib.abc.Finder"><code class="xref py py-class docutils literal notranslate"><span class="pre">Finder</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="method">
<dt id="importlib.abc.MetaPathFinder.find_spec">
<code class="sig-name descname">find_spec</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em>, <em class="sig-param">target=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.MetaPathFinder.find_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method for finding a <a class="reference internal" href="../glossary.html#term-module-spec"><span class="xref std std-term">spec</span></a> for
the specified module.  If this is a top-level import, <em>path</em> will
be <code class="docutils literal notranslate"><span class="pre">None</span></code>.  Otherwise, this is a search for a subpackage or
module and <em>path</em> will be the value of <a class="reference internal" href="../reference/import.html#__path__" title="__path__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__path__</span></code></a> from the
parent package. If a spec cannot be found, <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned.
When passed in, <code class="docutils literal notranslate"><span class="pre">target</span></code> is a module object that the finder may
use to make a more educated guess about what spec to return.
<a class="reference internal" href="#importlib.util.spec_from_loader" title="importlib.util.spec_from_loader"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.spec_from_loader()</span></code></a> may be useful for implementing
concrete <code class="docutils literal notranslate"><span class="pre">MetaPathFinders</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.MetaPathFinder.find_module">
<code class="sig-name descname">find_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.MetaPathFinder.find_module" title="Permalink to this definition">¶</a></dt>
<dd><p>A legacy method for finding a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> for the specified
module.  If this is a top-level import, <em>path</em> will be <code class="docutils literal notranslate"><span class="pre">None</span></code>.
Otherwise, this is a search for a subpackage or module and <em>path</em>
will be the value of <a class="reference internal" href="../reference/import.html#__path__" title="__path__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__path__</span></code></a> from the parent
package. If a loader cannot be found, <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned.</p>
<p>If <a class="reference internal" href="#importlib.abc.MetaPathFinder.find_spec" title="importlib.abc.MetaPathFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> is defined, backwards-compatible functionality is
provided.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> when called instead of raising
<a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>. Can use <a class="reference internal" href="#importlib.abc.MetaPathFinder.find_spec" title="importlib.abc.MetaPathFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> to provide
functionality.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.abc.MetaPathFinder.find_spec" title="importlib.abc.MetaPathFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.MetaPathFinder.invalidate_caches">
<code class="sig-name descname">invalidate_caches</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.MetaPathFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt>
<dd><p>An optional method which, when called, should invalidate any internal
cache used by the finder. Used by <a class="reference internal" href="#importlib.invalidate_caches" title="importlib.invalidate_caches"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.invalidate_caches()</span></code></a>
when invalidating the caches of all finders on <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> when called instead of <code class="docutils literal notranslate"><span class="pre">NotImplemented</span></code>.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.PathEntryFinder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">PathEntryFinder</code><a class="headerlink" href="#importlib.abc.PathEntryFinder" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class representing a <a class="reference internal" href="../glossary.html#term-path-entry-finder"><span class="xref std std-term">path entry finder</span></a>.  Though
it bears some similarities to <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">MetaPathFinder</span></code></a>, <code class="docutils literal notranslate"><span class="pre">PathEntryFinder</span></code>
is meant for use only within the path-based import subsystem provided
by <code class="xref py py-class docutils literal notranslate"><span class="pre">PathFinder</span></code>. This ABC is a subclass of <a class="reference internal" href="#importlib.abc.Finder" title="importlib.abc.Finder"><code class="xref py py-class docutils literal notranslate"><span class="pre">Finder</span></code></a> for
compatibility reasons only.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="method">
<dt id="importlib.abc.PathEntryFinder.find_spec">
<code class="sig-name descname">find_spec</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">target=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.PathEntryFinder.find_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method for finding a <a class="reference internal" href="../glossary.html#term-module-spec"><span class="xref std std-term">spec</span></a> for
the specified module.  The finder will search for the module only
within the <a class="reference internal" href="../glossary.html#term-path-entry"><span class="xref std std-term">path entry</span></a> to which it is assigned.  If a spec
cannot be found, <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned.  When passed in, <code class="docutils literal notranslate"><span class="pre">target</span></code>
is a module object that the finder may use to make a more educated
guess about what spec to return. <a class="reference internal" href="#importlib.util.spec_from_loader" title="importlib.util.spec_from_loader"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.spec_from_loader()</span></code></a>
may be useful for implementing concrete <code class="docutils literal notranslate"><span class="pre">PathEntryFinders</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.PathEntryFinder.find_loader">
<code class="sig-name descname">find_loader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.PathEntryFinder.find_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>A legacy method for finding a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> for the specified
module.  Returns a 2-tuple of <code class="docutils literal notranslate"><span class="pre">(loader,</span> <span class="pre">portion)</span></code> where <code class="docutils literal notranslate"><span class="pre">portion</span></code>
is a sequence of file system locations contributing to part of a namespace
package. The loader may be <code class="docutils literal notranslate"><span class="pre">None</span></code> while specifying <code class="docutils literal notranslate"><span class="pre">portion</span></code> to
signify the contribution of the file system locations to a namespace
package. An empty list can be used for <code class="docutils literal notranslate"><span class="pre">portion</span></code> to signify the loader
is not part of a namespace package. If <code class="docutils literal notranslate"><span class="pre">loader</span></code> is <code class="docutils literal notranslate"><span class="pre">None</span></code> and
<code class="docutils literal notranslate"><span class="pre">portion</span></code> is the empty list then no loader or location for a namespace
package were found (i.e. failure to find anything for the module).</p>
<p>If <a class="reference internal" href="#importlib.abc.PathEntryFinder.find_spec" title="importlib.abc.PathEntryFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> is defined then backwards-compatible functionality is
provided.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Returns <code class="docutils literal notranslate"><span class="pre">(None,</span> <span class="pre">[])</span></code> instead of raising <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.
Uses <a class="reference internal" href="#importlib.abc.PathEntryFinder.find_spec" title="importlib.abc.PathEntryFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> when available to provide functionality.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.abc.PathEntryFinder.find_spec" title="importlib.abc.PathEntryFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.PathEntryFinder.find_module">
<code class="sig-name descname">find_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.PathEntryFinder.find_module" title="Permalink to this definition">¶</a></dt>
<dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.Finder.find_module" title="importlib.abc.Finder.find_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Finder.find_module()</span></code></a> which is
equivalent to <code class="docutils literal notranslate"><span class="pre">self.find_loader(fullname)[0]</span></code>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.abc.PathEntryFinder.find_spec" title="importlib.abc.PathEntryFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.PathEntryFinder.invalidate_caches">
<code class="sig-name descname">invalidate_caches</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.PathEntryFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt>
<dd><p>An optional method which, when called, should invalidate any internal
cache used by the finder. Used by <code class="xref py py-meth docutils literal notranslate"><span class="pre">PathFinder.invalidate_caches()</span></code>
when invalidating the caches of all cached finders.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.Loader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">Loader</code><a class="headerlink" href="#importlib.abc.Loader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a>.
See <span class="target" id="index-13"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> for the exact definition for a loader.</p>
<p>Loaders that wish to support resource reading should implement a
<code class="docutils literal notranslate"><span class="pre">get_resource_reader(fullname)</span></code> method as specified by
<a class="reference internal" href="#importlib.abc.ResourceReader" title="importlib.abc.ResourceReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.ResourceReader</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.7: </span>Introduced the optional <code class="docutils literal notranslate"><span class="pre">get_resource_reader()</span></code> method.</p>
</div>
<dl class="method">
<dt id="importlib.abc.Loader.create_module">
<code class="sig-name descname">create_module</code><span class="sig-paren">(</span><em class="sig-param">spec</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.Loader.create_module" title="Permalink to this definition">¶</a></dt>
<dd><p>A method that returns the module object to use when
importing a module.  This method may return <code class="docutils literal notranslate"><span class="pre">None</span></code>,
indicating that default module creation semantics should take place.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>Starting in Python 3.6, this method will not be optional when
<a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> is defined.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.Loader.exec_module">
<code class="sig-name descname">exec_module</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.Loader.exec_module" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method that executes the module in its own namespace
when a module is imported or reloaded.  The module should already
be initialized when <code class="docutils literal notranslate"><span class="pre">exec_module()</span></code> is called. When this method exists,
<a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code></a> must be defined.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.6: </span><a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code></a> must also be defined.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.Loader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.Loader.load_module" title="Permalink to this definition">¶</a></dt>
<dd><p>A legacy method for loading a module. If the module cannot be
loaded, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> is raised, otherwise the loaded module is
returned.</p>
<p>If the requested module already exists in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>, that
module should be used and reloaded.
Otherwise the loader should create a new module and insert it into
<a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a> before any loading begins, to prevent recursion
from the import. If the loader inserted a module and the load fails, it
must be removed by the loader from <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>; modules already
in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a> before the loader began execution should be left
alone (see <a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.module_for_loader()</span></code></a>).</p>
<p>The loader should set several attributes on the module.
(Note that some of these attributes can change when a module is
reloaded):</p>
<ul class="simple">
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__name__" title="__name__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__name__</span></code></a></dt><dd><p>The name of the module.</p>
</dd>
</dl>
</li>
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__file__" title="__file__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__file__</span></code></a></dt><dd><p>The path to where the module data is stored (not set for built-in
modules).</p>
</dd>
</dl>
</li>
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__cached__" title="__cached__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__cached__</span></code></a></dt><dd><p>The path to where a compiled version of the module is/should be
stored (not set when the attribute would be inappropriate).</p>
</dd>
</dl>
</li>
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__path__" title="__path__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__path__</span></code></a></dt><dd><p>A list of strings specifying the search path within a
package. This attribute is not set on modules.</p>
</dd>
</dl>
</li>
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a></dt><dd><p>The fully-qualified name of the package under which the module was
loaded as a submodule (or the empty string for top-level modules).
For packages, it is the same as <a class="reference internal" href="../reference/import.html#__name__" title="__name__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__name__</span></code></a>.  The
<a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.module_for_loader()</span></code></a> decorator can handle the
details for <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a>.</p>
</dd>
</dl>
</li>
<li><dl class="simple">
<dt><a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a></dt><dd><p>The loader used to load the module. The
<a class="reference internal" href="#importlib.util.module_for_loader" title="importlib.util.module_for_loader"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.module_for_loader()</span></code></a> decorator can handle the
details for <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a>.</p>
</dd>
</dl>
</li>
</ul>
<p>When <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> is available then backwards-compatible
functionality is provided.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raise <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> when called instead of
<a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>. Functionality provided when
<a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> is available.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>The recommended API for loading a module is <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a>
(and <a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code></a>).  Loaders should implement
it instead of load_module().  The import machinery takes care of
all the other responsibilities of load_module() when exec_module()
is implemented.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.Loader.module_repr">
<code class="sig-name descname">module_repr</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.Loader.module_repr" title="Permalink to this definition">¶</a></dt>
<dd><p>A legacy method which when implemented calculates and returns the
given module’s repr, as a string. The module type’s default repr() will
use the result of this method as appropriate.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Made optional instead of an abstractmethod.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>The import machinery now takes care of this automatically.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.ResourceReader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">ResourceReader</code><a class="headerlink" href="#importlib.abc.ResourceReader" title="Permalink to this definition">¶</a></dt>
<dd><p>An <a class="reference internal" href="../glossary.html#term-abstract-base-class"><span class="xref std std-term">abstract base class</span></a> to provide the ability to read
<em>resources</em>.</p>
<p>From the perspective of this ABC, a <em>resource</em> is a binary
artifact that is shipped within a package. Typically this is
something like a data file that lives next to the <code class="docutils literal notranslate"><span class="pre">__init__.py</span></code>
file of the package. The purpose of this class is to help abstract
out the accessing of such data files so that it does not matter if
the package and its data file(s) are stored in a e.g. zip file
versus on the file system.</p>
<p>For any of methods of this class, a <em>resource</em> argument is
expected to be a <a class="reference internal" href="../glossary.html#term-path-like-object"><span class="xref std std-term">path-like object</span></a> which represents
conceptually just a file name. This means that no subdirectory
paths should be included in the <em>resource</em> argument. This is
because the location of the package the reader is for, acts as the
“directory”. Hence the metaphor for directories and file
names is packages and resources, respectively. This is also why
instances of this class are expected to directly correlate to
a specific package (instead of potentially representing multiple
packages or a module).</p>
<p>Loaders that wish to support resource reading are expected to
provide a method called <code class="docutils literal notranslate"><span class="pre">get_resource_reader(fullname)</span></code> which
returns an object implementing this ABC’s interface. If the module
specified by fullname is not a package, this method should return
<a class="reference internal" href="constants.html#None" title="None"><code class="xref py py-const docutils literal notranslate"><span class="pre">None</span></code></a>. An object compatible with this ABC should only be
returned when the specified module is a package.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.7.</span></p>
</div>
<dl class="method">
<dt id="importlib.abc.ResourceReader.open_resource">
<em class="property">abstractmethod </em><code class="sig-name descname">open_resource</code><span class="sig-paren">(</span><em class="sig-param">resource</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ResourceReader.open_resource" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns an opened, <a class="reference internal" href="../glossary.html#term-file-like-object"><span class="xref std std-term">file-like object</span></a> for binary reading
of the <em>resource</em>.</p>
<p>If the resource cannot be found, <a class="reference internal" href="exceptions.html#FileNotFoundError" title="FileNotFoundError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">FileNotFoundError</span></code></a> is
raised.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.ResourceReader.resource_path">
<em class="property">abstractmethod </em><code class="sig-name descname">resource_path</code><span class="sig-paren">(</span><em class="sig-param">resource</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ResourceReader.resource_path" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the file system path to the <em>resource</em>.</p>
<p>If the resource does not concretely exist on the file system,
raise <a class="reference internal" href="exceptions.html#FileNotFoundError" title="FileNotFoundError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">FileNotFoundError</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.ResourceReader.is_resource">
<em class="property">abstractmethod </em><code class="sig-name descname">is_resource</code><span class="sig-paren">(</span><em class="sig-param">name</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ResourceReader.is_resource" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <code class="docutils literal notranslate"><span class="pre">True</span></code> if the named <em>name</em> is considered a resource.
<a class="reference internal" href="exceptions.html#FileNotFoundError" title="FileNotFoundError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">FileNotFoundError</span></code></a> is raised if <em>name</em> does not exist.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.ResourceReader.contents">
<em class="property">abstractmethod </em><code class="sig-name descname">contents</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ResourceReader.contents" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns an <a class="reference internal" href="../glossary.html#term-iterable"><span class="xref std std-term">iterable</span></a> of strings over the contents of
the package. Do note that it is not required that all names
returned by the iterator be actual resources, e.g. it is
acceptable to return names for which <a class="reference internal" href="#importlib.abc.ResourceReader.is_resource" title="importlib.abc.ResourceReader.is_resource"><code class="xref py py-meth docutils literal notranslate"><span class="pre">is_resource()</span></code></a> would
be false.</p>
<p>Allowing non-resource names to be returned is to allow for
situations where how a package and its resources are stored
are known a priori and the non-resource names would be useful.
For instance, returning subdirectory names is allowed so that
when it is known that the package and resources are stored on
the file system then those subdirectory names can be used
directly.</p>
<p>The abstract method returns an iterable of no items.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.ResourceLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">ResourceLoader</code><a class="headerlink" href="#importlib.abc.ResourceLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> which implements the optional
<span class="target" id="index-14"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol for loading arbitrary resources from the storage
back-end.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.7: </span>This ABC is deprecated in favour of supporting resource loading
through <a class="reference internal" href="#importlib.abc.ResourceReader" title="importlib.abc.ResourceReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.ResourceReader</span></code></a>.</p>
</div>
<dl class="method">
<dt id="importlib.abc.ResourceLoader.get_data">
<em class="property">abstractmethod </em><code class="sig-name descname">get_data</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ResourceLoader.get_data" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method to return the bytes for the data located at <em>path</em>.
Loaders that have a file-like storage back-end
that allows storing arbitrary data
can implement this abstract method to give direct access
to the data stored. <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> is to be raised if the <em>path</em> cannot
be found. The <em>path</em> is expected to be constructed using a module’s
<a class="reference internal" href="../reference/import.html#__file__" title="__file__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__file__</span></code></a> attribute or an item from a package’s <a class="reference internal" href="../reference/import.html#__path__" title="__path__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__path__</span></code></a>.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raises <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.InspectLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">InspectLoader</code><a class="headerlink" href="#importlib.abc.InspectLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class for a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> which implements the optional
<span class="target" id="index-15"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol for loaders that inspect modules.</p>
<dl class="method">
<dt id="importlib.abc.InspectLoader.get_code">
<code class="sig-name descname">get_code</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.get_code" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the code object for a module, or <code class="docutils literal notranslate"><span class="pre">None</span></code> if the module does not
have a code object (as would be the case, for example, for a built-in
module).  Raise an <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> if loader cannot find the
requested module.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>While the method has a default implementation, it is suggested that
it be overridden if possible for performance.</p>
</div>
<div class="versionchanged" id="index-16">
<p><span class="versionmodified changed">Changed in version 3.4: </span>No longer abstract and a concrete implementation is provided.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.InspectLoader.get_source">
<em class="property">abstractmethod </em><code class="sig-name descname">get_source</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.get_source" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method to return the source of a module. It is returned as
a text string using <a class="reference internal" href="../glossary.html#term-universal-newlines"><span class="xref std std-term">universal newlines</span></a>, translating all
recognized line separators into <code class="docutils literal notranslate"><span class="pre">'\n'</span></code> characters.  Returns <code class="docutils literal notranslate"><span class="pre">None</span></code>
if no source is available (e.g. a built-in module). Raises
<a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> if the loader cannot find the module specified.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.InspectLoader.is_package">
<code class="sig-name descname">is_package</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.is_package" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method to return a true value if the module is a package, a
false value otherwise. <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> is raised if the
<a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> cannot find the module.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.InspectLoader.source_to_code">
<em class="property">static </em><code class="sig-name descname">source_to_code</code><span class="sig-paren">(</span><em class="sig-param">data</em>, <em class="sig-param">path='&lt;string&gt;'</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.source_to_code" title="Permalink to this definition">¶</a></dt>
<dd><p>Create a code object from Python source.</p>
<p>The <em>data</em> argument can be whatever the <a class="reference internal" href="functions.html#compile" title="compile"><code class="xref py py-func docutils literal notranslate"><span class="pre">compile()</span></code></a> function
supports (i.e. string or bytes). The <em>path</em> argument should be
the “path” to where the source code originated from, which can be an
abstract concept (e.g. location in a zip file).</p>
<p>With the subsequent code object one can execute it in a module by
running <code class="docutils literal notranslate"><span class="pre">exec(code,</span> <span class="pre">module.__dict__)</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>Made the method static.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.InspectLoader.exec_module">
<code class="sig-name descname">exec_module</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.exec_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Implementation of <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.exec_module()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.InspectLoader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.InspectLoader.load_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.load_module()</span></code></a>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>use <a class="reference internal" href="#importlib.abc.InspectLoader.exec_module" title="importlib.abc.InspectLoader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> instead.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.ExecutionLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">ExecutionLoader</code><a class="headerlink" href="#importlib.abc.ExecutionLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class which inherits from <a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">InspectLoader</span></code></a> that,
when implemented, helps a module to be executed as a script. The ABC
represents an optional <span class="target" id="index-17"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0302"><strong>PEP 302</strong></a> protocol.</p>
<dl class="method">
<dt id="importlib.abc.ExecutionLoader.get_filename">
<em class="property">abstractmethod </em><code class="sig-name descname">get_filename</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.ExecutionLoader.get_filename" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract method that is to return the value of <a class="reference internal" href="../reference/import.html#__file__" title="__file__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__file__</span></code></a> for
the specified module. If no path is available, <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> is
raised.</p>
<p>If source code is available, then the method should return the path to
the source file, regardless of whether a bytecode was used to load the
module.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raises <a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.FileLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">FileLoader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.FileLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class which inherits from <a class="reference internal" href="#importlib.abc.ResourceLoader" title="importlib.abc.ResourceLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">ResourceLoader</span></code></a> and
<a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">ExecutionLoader</span></code></a>, providing concrete implementations of
<a class="reference internal" href="#importlib.abc.ResourceLoader.get_data" title="importlib.abc.ResourceLoader.get_data"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ResourceLoader.get_data()</span></code></a> and <a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ExecutionLoader.get_filename()</span></code></a>.</p>
<p>The <em>fullname</em> argument is a fully resolved name of the module the loader is
to handle. The <em>path</em> argument is the path to the file for the module.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.abc.FileLoader.name">
<code class="sig-name descname">name</code><a class="headerlink" href="#importlib.abc.FileLoader.name" title="Permalink to this definition">¶</a></dt>
<dd><p>The name of the module the loader can handle.</p>
</dd></dl>

<dl class="attribute">
<dt id="importlib.abc.FileLoader.path">
<code class="sig-name descname">path</code><a class="headerlink" href="#importlib.abc.FileLoader.path" title="Permalink to this definition">¶</a></dt>
<dd><p>Path to the file of the module.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.FileLoader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.FileLoader.load_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Calls super’s <code class="docutils literal notranslate"><span class="pre">load_module()</span></code>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.exec_module()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.FileLoader.get_filename">
<em class="property">abstractmethod </em><code class="sig-name descname">get_filename</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.FileLoader.get_filename" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <a class="reference internal" href="#importlib.abc.FileLoader.path" title="importlib.abc.FileLoader.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.FileLoader.get_data">
<em class="property">abstractmethod </em><code class="sig-name descname">get_data</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.FileLoader.get_data" title="Permalink to this definition">¶</a></dt>
<dd><p>Reads <em>path</em> as a binary file and returns the bytes from it.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.abc.SourceLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.abc.</code><code class="sig-name descname">SourceLoader</code><a class="headerlink" href="#importlib.abc.SourceLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>An abstract base class for implementing source (and optionally bytecode)
file loading. The class inherits from both <a class="reference internal" href="#importlib.abc.ResourceLoader" title="importlib.abc.ResourceLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">ResourceLoader</span></code></a> and
<a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">ExecutionLoader</span></code></a>, requiring the implementation of:</p>
<ul class="simple">
<li><p><a class="reference internal" href="#importlib.abc.ResourceLoader.get_data" title="importlib.abc.ResourceLoader.get_data"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ResourceLoader.get_data()</span></code></a></p></li>
<li><dl class="simple">
<dt><a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ExecutionLoader.get_filename()</span></code></a></dt><dd><p>Should only return the path to the source file; sourceless
loading is not supported.</p>
</dd>
</dl>
</li>
</ul>
<p>The abstract methods defined by this class are to add optional bytecode
file support. Not implementing these optional methods (or causing them to
raise <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>) causes the loader to
only work with source code. Implementing the methods allows the loader to
work with source <em>and</em> bytecode files; it does not allow for <em>sourceless</em>
loading where only bytecode is provided.  Bytecode files are an
optimization to speed up loading by removing the parsing step of Python’s
compiler, and so no bytecode-specific API is exposed.</p>
<dl class="method">
<dt id="importlib.abc.SourceLoader.path_stats">
<code class="sig-name descname">path_stats</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.path_stats" title="Permalink to this definition">¶</a></dt>
<dd><p>Optional abstract method which returns a <a class="reference internal" href="stdtypes.html#dict" title="dict"><code class="xref py py-class docutils literal notranslate"><span class="pre">dict</span></code></a> containing
metadata about the specified path.  Supported dictionary keys are:</p>
<ul class="simple">
<li><p><code class="docutils literal notranslate"><span class="pre">'mtime'</span></code> (mandatory): an integer or floating-point number
representing the modification time of the source code;</p></li>
<li><p><code class="docutils literal notranslate"><span class="pre">'size'</span></code> (optional): the size in bytes of the source code.</p></li>
</ul>
<p>Any other keys in the dictionary are ignored, to allow for future
extensions. If the path cannot be handled, <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> is raised.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raise <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.path_mtime">
<code class="sig-name descname">path_mtime</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.path_mtime" title="Permalink to this definition">¶</a></dt>
<dd><p>Optional abstract method which returns the modification time for the
specified path.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.3: </span>This method is deprecated in favour of <a class="reference internal" href="#importlib.abc.SourceLoader.path_stats" title="importlib.abc.SourceLoader.path_stats"><code class="xref py py-meth docutils literal notranslate"><span class="pre">path_stats()</span></code></a>.  You don’t
have to implement it, but it is still available for compatibility
purposes. Raise <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> if the path cannot be handled.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Raise <a class="reference internal" href="exceptions.html#OSError" title="OSError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">OSError</span></code></a> instead of <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.set_data">
<code class="sig-name descname">set_data</code><span class="sig-paren">(</span><em class="sig-param">path</em>, <em class="sig-param">data</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.set_data" title="Permalink to this definition">¶</a></dt>
<dd><p>Optional abstract method which writes the specified bytes to a file
path. Any intermediate directories which do not exist are to be created
automatically.</p>
<p>When writing to the path fails because the path is read-only
(<a class="reference internal" href="errno.html#errno.EACCES" title="errno.EACCES"><code class="xref py py-attr docutils literal notranslate"><span class="pre">errno.EACCES</span></code></a>/<a class="reference internal" href="exceptions.html#PermissionError" title="PermissionError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">PermissionError</span></code></a>), do not propagate the
exception.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>No longer raises <a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a> when called.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.get_code">
<code class="sig-name descname">get_code</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.get_code" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_code" title="importlib.abc.InspectLoader.get_code"><code class="xref py py-meth docutils literal notranslate"><span class="pre">InspectLoader.get_code()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.exec_module">
<code class="sig-name descname">exec_module</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.exec_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.exec_module()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.load_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.load_module()</span></code></a>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.abc.SourceLoader.exec_module" title="importlib.abc.SourceLoader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.get_source">
<code class="sig-name descname">get_source</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.get_source" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.get_source" title="importlib.abc.InspectLoader.get_source"><code class="xref py py-meth docutils literal notranslate"><span class="pre">InspectLoader.get_source()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.abc.SourceLoader.is_package">
<code class="sig-name descname">is_package</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.abc.SourceLoader.is_package" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.InspectLoader.is_package" title="importlib.abc.InspectLoader.is_package"><code class="xref py py-meth docutils literal notranslate"><span class="pre">InspectLoader.is_package()</span></code></a>. A module
is determined to be a package if its file path (as provided by
<a class="reference internal" href="#importlib.abc.ExecutionLoader.get_filename" title="importlib.abc.ExecutionLoader.get_filename"><code class="xref py py-meth docutils literal notranslate"><span class="pre">ExecutionLoader.get_filename()</span></code></a>) is a file named
<code class="docutils literal notranslate"><span class="pre">__init__</span></code> when the file extension is removed <strong>and</strong> the module name
itself does not end in <code class="docutils literal notranslate"><span class="pre">__init__</span></code>.</p>
</dd></dl>

</dd></dl>

</div>
<div class="section" id="module-importlib.resources">
<span id="importlib-resources-resources"></span><h2><a class="reference internal" href="#module-importlib.resources" title="importlib.resources: Package resource reading, opening, and access"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.resources</span></code></a> – Resources<a class="headerlink" href="#module-importlib.resources" title="Permalink to this headline">¶</a></h2>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.8/Lib/importlib/resources.py">Lib/importlib/resources.py</a></p>
<hr class="docutils" />
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.7.</span></p>
</div>
<p>This module leverages Python’s import system to provide access to <em>resources</em>
within <em>packages</em>.  If you can import a package, you can access resources
within that package.  Resources can be opened or read, in either binary or
text mode.</p>
<p>Resources are roughly akin to files inside directories, though it’s important
to keep in mind that this is just a metaphor.  Resources and packages <strong>do
not</strong> have to exist as physical files and directories on the file system.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>This module provides functionality similar to <a class="reference external" href="https://setuptools.readthedocs.io/en/latest/pkg_resources.html">pkg_resources</a> <a class="reference external" href="http://setuptools.readthedocs.io/en/latest/pkg_resources.html#basic-resource-access">Basic
Resource Access</a>
without the performance overhead of that package.  This makes reading
resources included in packages easier, with more stable and consistent
semantics.</p>
<p>The standalone backport of this module provides more information
on <a class="reference external" href="http://importlib-resources.readthedocs.io/en/latest/using.html">using importlib.resources</a> and
<a class="reference external" href="http://importlib-resources.readthedocs.io/en/latest/migration.html">migrating from pkg_resources to importlib.resources</a>.</p>
</div>
<p>Loaders that wish to support resource reading should implement a
<code class="docutils literal notranslate"><span class="pre">get_resource_reader(fullname)</span></code> method as specified by
<a class="reference internal" href="#importlib.abc.ResourceReader" title="importlib.abc.ResourceReader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.ResourceReader</span></code></a>.</p>
<p>The following types are defined.</p>
<dl class="data">
<dt id="importlib.resources.Package">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">Package</code><a class="headerlink" href="#importlib.resources.Package" title="Permalink to this definition">¶</a></dt>
<dd><p>The <code class="docutils literal notranslate"><span class="pre">Package</span></code> type is defined as <code class="docutils literal notranslate"><span class="pre">Union[str,</span> <span class="pre">ModuleType]</span></code>.  This means
that where the function describes accepting a <code class="docutils literal notranslate"><span class="pre">Package</span></code>, you can pass in
either a string or a module.  Module objects must have a resolvable
<code class="docutils literal notranslate"><span class="pre">__spec__.submodule_search_locations</span></code> that is not <code class="docutils literal notranslate"><span class="pre">None</span></code>.</p>
</dd></dl>

<dl class="data">
<dt id="importlib.resources.Resource">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">Resource</code><a class="headerlink" href="#importlib.resources.Resource" title="Permalink to this definition">¶</a></dt>
<dd><p>This type describes the resource names passed into the various functions
in this package.  This is defined as <code class="docutils literal notranslate"><span class="pre">Union[str,</span> <span class="pre">os.PathLike]</span></code>.</p>
</dd></dl>

<p>The following functions are available.</p>
<dl class="function">
<dt id="importlib.resources.open_binary">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">open_binary</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">resource</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.open_binary" title="Permalink to this definition">¶</a></dt>
<dd><p>Open for binary reading the <em>resource</em> within <em>package</em>.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.  <em>resource</em> is the name of the resource to open
within <em>package</em>; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  This function returns a
<code class="docutils literal notranslate"><span class="pre">typing.BinaryIO</span></code> instance, a binary I/O stream open for reading.</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.open_text">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">open_text</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">resource</em>, <em class="sig-param">encoding='utf-8'</em>, <em class="sig-param">errors='strict'</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.open_text" title="Permalink to this definition">¶</a></dt>
<dd><p>Open for text reading the <em>resource</em> within <em>package</em>.  By default, the
resource is opened for reading as UTF-8.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.  <em>resource</em> is the name of the resource to open
within <em>package</em>; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  <em>encoding</em> and <em>errors</em>
have the same meaning as with built-in <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-func docutils literal notranslate"><span class="pre">open()</span></code></a>.</p>
<p>This function returns a <code class="docutils literal notranslate"><span class="pre">typing.TextIO</span></code> instance, a text I/O stream open
for reading.</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.read_binary">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">read_binary</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">resource</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.read_binary" title="Permalink to this definition">¶</a></dt>
<dd><p>Read and return the contents of the <em>resource</em> within <em>package</em> as
<code class="docutils literal notranslate"><span class="pre">bytes</span></code>.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.  <em>resource</em> is the name of the resource to open
within <em>package</em>; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  This function returns the
contents of the resource as <a class="reference internal" href="stdtypes.html#bytes" title="bytes"><code class="xref py py-class docutils literal notranslate"><span class="pre">bytes</span></code></a>.</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.read_text">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">read_text</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">resource</em>, <em class="sig-param">encoding='utf-8'</em>, <em class="sig-param">errors='strict'</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.read_text" title="Permalink to this definition">¶</a></dt>
<dd><p>Read and return the contents of <em>resource</em> within <em>package</em> as a <code class="docutils literal notranslate"><span class="pre">str</span></code>.
By default, the contents are read as strict UTF-8.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.  <em>resource</em> is the name of the resource to open
within <em>package</em>; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).  <em>encoding</em> and <em>errors</em>
have the same meaning as with built-in <a class="reference internal" href="functions.html#open" title="open"><code class="xref py py-func docutils literal notranslate"><span class="pre">open()</span></code></a>.  This function
returns the contents of the resource as <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a>.</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.path">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">path</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">resource</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.path" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the path to the <em>resource</em> as an actual file system path.  This
function returns a context manager for use in a <a class="reference internal" href="../reference/compound_stmts.html#with"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">with</span></code></a> statement.
The context manager provides a <a class="reference internal" href="pathlib.html#pathlib.Path" title="pathlib.Path"><code class="xref py py-class docutils literal notranslate"><span class="pre">pathlib.Path</span></code></a> object.</p>
<p>Exiting the context manager cleans up any temporary file created when the
resource needs to be extracted from e.g. a zip file.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.  <em>resource</em> is the name of the resource to open
within <em>package</em>; it may not contain path separators and it may not have
sub-resources (i.e. it cannot be a directory).</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.is_resource">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">is_resource</code><span class="sig-paren">(</span><em class="sig-param">package</em>, <em class="sig-param">name</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.is_resource" title="Permalink to this definition">¶</a></dt>
<dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if there is a resource named <em>name</em> in the package,
otherwise <code class="docutils literal notranslate"><span class="pre">False</span></code>.  Remember that directories are <em>not</em> resources!
<em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.</p>
</dd></dl>

<dl class="function">
<dt id="importlib.resources.contents">
<code class="sig-prename descclassname">importlib.resources.</code><code class="sig-name descname">contents</code><span class="sig-paren">(</span><em class="sig-param">package</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.resources.contents" title="Permalink to this definition">¶</a></dt>
<dd><p>Return an iterable over the named items within the package.  The iterable
returns <a class="reference internal" href="stdtypes.html#str" title="str"><code class="xref py py-class docutils literal notranslate"><span class="pre">str</span></code></a> resources (e.g. files) and non-resources
(e.g. directories).  The iterable does not recurse into subdirectories.</p>
<p><em>package</em> is either a name or a module object which conforms to the
<code class="docutils literal notranslate"><span class="pre">Package</span></code> requirements.</p>
</dd></dl>

</div>
<div class="section" id="module-importlib.machinery">
<span id="importlib-machinery-importers-and-path-hooks"></span><h2><a class="reference internal" href="#module-importlib.machinery" title="importlib.machinery: Importers and path hooks"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.machinery</span></code></a> – Importers and path hooks<a class="headerlink" href="#module-importlib.machinery" title="Permalink to this headline">¶</a></h2>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.8/Lib/importlib/machinery.py">Lib/importlib/machinery.py</a></p>
<hr class="docutils" />
<p>This module contains the various objects that help <a class="reference internal" href="../reference/simple_stmts.html#import"><code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a>
find and load modules.</p>
<dl class="attribute">
<dt id="importlib.machinery.SOURCE_SUFFIXES">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">SOURCE_SUFFIXES</code><a class="headerlink" href="#importlib.machinery.SOURCE_SUFFIXES" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of strings representing the recognized file suffixes for source
modules.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.DEBUG_BYTECODE_SUFFIXES">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">DEBUG_BYTECODE_SUFFIXES</code><a class="headerlink" href="#importlib.machinery.DEBUG_BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of strings representing the file suffixes for non-optimized bytecode
modules.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.5: </span>Use <a class="reference internal" href="#importlib.machinery.BYTECODE_SUFFIXES" title="importlib.machinery.BYTECODE_SUFFIXES"><code class="xref py py-attr docutils literal notranslate"><span class="pre">BYTECODE_SUFFIXES</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">OPTIMIZED_BYTECODE_SUFFIXES</code><a class="headerlink" href="#importlib.machinery.OPTIMIZED_BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of strings representing the file suffixes for optimized bytecode
modules.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.5: </span>Use <a class="reference internal" href="#importlib.machinery.BYTECODE_SUFFIXES" title="importlib.machinery.BYTECODE_SUFFIXES"><code class="xref py py-attr docutils literal notranslate"><span class="pre">BYTECODE_SUFFIXES</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.BYTECODE_SUFFIXES">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">BYTECODE_SUFFIXES</code><a class="headerlink" href="#importlib.machinery.BYTECODE_SUFFIXES" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of strings representing the recognized file suffixes for bytecode
modules (including the leading dot).</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>The value is no longer dependent on <code class="docutils literal notranslate"><span class="pre">__debug__</span></code>.</p>
</div>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.EXTENSION_SUFFIXES">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">EXTENSION_SUFFIXES</code><a class="headerlink" href="#importlib.machinery.EXTENSION_SUFFIXES" title="Permalink to this definition">¶</a></dt>
<dd><p>A list of strings representing the recognized file suffixes for
extension modules.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.machinery.all_suffixes">
<code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">all_suffixes</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.all_suffixes" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns a combined list of strings representing all file suffixes for
modules recognized by the standard import machinery. This is a
helper for code which simply needs to know if a filesystem path
potentially refers to a module without needing any details on the kind
of module (for example, <a class="reference internal" href="inspect.html#inspect.getmodulename" title="inspect.getmodulename"><code class="xref py py-func docutils literal notranslate"><span class="pre">inspect.getmodulename()</span></code></a>).</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.BuiltinImporter">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">BuiltinImporter</code><a class="headerlink" href="#importlib.machinery.BuiltinImporter" title="Permalink to this definition">¶</a></dt>
<dd><p>An <a class="reference internal" href="../glossary.html#term-importer"><span class="xref std std-term">importer</span></a> for built-in modules. All known built-in modules are
listed in <a class="reference internal" href="sys.html#sys.builtin_module_names" title="sys.builtin_module_names"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.builtin_module_names</span></code></a>. This class implements the
<a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.MetaPathFinder</span></code></a> and
<a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.InspectLoader</span></code></a> ABCs.</p>
<p>Only class methods are defined by this class to alleviate the need for
instantiation.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>As part of <span class="target" id="index-18"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0489"><strong>PEP 489</strong></a>, the builtin importer now implements
<code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.create_module()</span></code> and <code class="xref py py-meth docutils literal notranslate"><span class="pre">Loader.exec_module()</span></code></p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.FrozenImporter">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">FrozenImporter</code><a class="headerlink" href="#importlib.machinery.FrozenImporter" title="Permalink to this definition">¶</a></dt>
<dd><p>An <a class="reference internal" href="../glossary.html#term-importer"><span class="xref std std-term">importer</span></a> for frozen modules. This class implements the
<a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.MetaPathFinder</span></code></a> and
<a class="reference internal" href="#importlib.abc.InspectLoader" title="importlib.abc.InspectLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.InspectLoader</span></code></a> ABCs.</p>
<p>Only class methods are defined by this class to alleviate the need for
instantiation.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Gained <code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code> and <code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code>
methods.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.WindowsRegistryFinder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">WindowsRegistryFinder</code><a class="headerlink" href="#importlib.machinery.WindowsRegistryFinder" title="Permalink to this definition">¶</a></dt>
<dd><p><a class="reference internal" href="../glossary.html#term-finder"><span class="xref std std-term">Finder</span></a> for modules declared in the Windows registry.  This class
implements the <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.MetaPathFinder</span></code></a> ABC.</p>
<p>Only class methods are defined by this class to alleviate the need for
instantiation.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.6: </span>Use <a class="reference internal" href="site.html#module-site" title="site: Module responsible for site-specific configuration."><code class="xref py py-mod docutils literal notranslate"><span class="pre">site</span></code></a> configuration instead. Future versions of Python may
not enable this finder by default.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.PathFinder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">PathFinder</code><a class="headerlink" href="#importlib.machinery.PathFinder" title="Permalink to this definition">¶</a></dt>
<dd><p>A <a class="reference internal" href="../glossary.html#term-finder"><span class="xref std std-term">Finder</span></a> for <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a> and package <code class="docutils literal notranslate"><span class="pre">__path__</span></code> attributes.
This class implements the <a class="reference internal" href="#importlib.abc.MetaPathFinder" title="importlib.abc.MetaPathFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.MetaPathFinder</span></code></a> ABC.</p>
<p>Only class methods are defined by this class to alleviate the need for
instantiation.</p>
<dl class="method">
<dt id="importlib.machinery.PathFinder.find_spec">
<em class="property">classmethod </em><code class="sig-name descname">find_spec</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path=None</em>, <em class="sig-param">target=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.PathFinder.find_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>Class method that attempts to find a <a class="reference internal" href="../glossary.html#term-module-spec"><span class="xref std std-term">spec</span></a>
for the module specified by <em>fullname</em> on <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path</span></code></a> or, if
defined, on <em>path</em>. For each path entry that is searched,
<a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a> is checked. If a non-false object
is found then it is used as the <a class="reference internal" href="../glossary.html#term-path-entry-finder"><span class="xref std std-term">path entry finder</span></a> to look
for the module being searched for. If no entry is found in
<a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a>, then <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_hooks</span></code></a> is
searched for a finder for the path entry and, if found, is stored
in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a> along with being queried about
the module. If no finder is ever found then <code class="docutils literal notranslate"><span class="pre">None</span></code> is both
stored in the cache and returned.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>If the current working directory – represented by an empty string –
is no longer valid then <code class="docutils literal notranslate"><span class="pre">None</span></code> is returned but no value is cached
in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a>.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.PathFinder.find_module">
<em class="property">classmethod </em><code class="sig-name descname">find_module</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.PathFinder.find_module" title="Permalink to this definition">¶</a></dt>
<dd><p>A legacy wrapper around <a class="reference internal" href="#importlib.machinery.PathFinder.find_spec" title="importlib.machinery.PathFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a>.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>Use <a class="reference internal" href="#importlib.machinery.PathFinder.find_spec" title="importlib.machinery.PathFinder.find_spec"><code class="xref py py-meth docutils literal notranslate"><span class="pre">find_spec()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.PathFinder.invalidate_caches">
<em class="property">classmethod </em><code class="sig-name descname">invalidate_caches</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.PathFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt>
<dd><p>Calls <a class="reference internal" href="#importlib.abc.PathEntryFinder.invalidate_caches" title="importlib.abc.PathEntryFinder.invalidate_caches"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.PathEntryFinder.invalidate_caches()</span></code></a> on all
finders stored in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a> that define the method.
Otherwise entries in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a> set to <code class="docutils literal notranslate"><span class="pre">None</span></code> are
deleted.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.7: </span>Entries of <code class="docutils literal notranslate"><span class="pre">None</span></code> in <a class="reference internal" href="sys.html#sys.path_importer_cache" title="sys.path_importer_cache"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_importer_cache</span></code></a> are deleted.</p>
</div>
</dd></dl>

<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Calls objects in <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.path_hooks</span></code></a> with the current working
directory for <code class="docutils literal notranslate"><span class="pre">''</span></code> (i.e. the empty string).</p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.FileFinder">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">FileFinder</code><span class="sig-paren">(</span><em class="sig-param">path</em>, <em class="sig-param">*loader_details</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.FileFinder" title="Permalink to this definition">¶</a></dt>
<dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.PathEntryFinder" title="importlib.abc.PathEntryFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.PathEntryFinder</span></code></a> which
caches results from the file system.</p>
<p>The <em>path</em> argument is the directory for which the finder is in charge of
searching.</p>
<p>The <em>loader_details</em> argument is a variable number of 2-item tuples each
containing a loader and a sequence of file suffixes the loader recognizes.
The loaders are expected to be callables which accept two arguments of
the module’s name and the path to the file found.</p>
<p>The finder will cache the directory contents as necessary, making stat calls
for each module search to verify the cache is not outdated. Because cache
staleness relies upon the granularity of the operating system’s state
information of the file system, there is a potential race condition of
searching for a module, creating a new file, and then searching for the
module the new file represents. If the operations happen fast enough to fit
within the granularity of stat calls, then the module search will fail. To
prevent this from happening, when you create a module dynamically, make sure
to call <a class="reference internal" href="#importlib.invalidate_caches" title="importlib.invalidate_caches"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.invalidate_caches()</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.machinery.FileFinder.path">
<code class="sig-name descname">path</code><a class="headerlink" href="#importlib.machinery.FileFinder.path" title="Permalink to this definition">¶</a></dt>
<dd><p>The path the finder will search in.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.FileFinder.find_spec">
<code class="sig-name descname">find_spec</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">target=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.FileFinder.find_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>Attempt to find the spec to handle <em>fullname</em> within <a class="reference internal" href="#importlib.machinery.FileFinder.path" title="importlib.machinery.FileFinder.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.FileFinder.find_loader">
<code class="sig-name descname">find_loader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.FileFinder.find_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>Attempt to find the loader to handle <em>fullname</em> within <a class="reference internal" href="#importlib.machinery.FileFinder.path" title="importlib.machinery.FileFinder.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.FileFinder.invalidate_caches">
<code class="sig-name descname">invalidate_caches</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.FileFinder.invalidate_caches" title="Permalink to this definition">¶</a></dt>
<dd><p>Clear out the internal cache.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.FileFinder.path_hook">
<em class="property">classmethod </em><code class="sig-name descname">path_hook</code><span class="sig-paren">(</span><em class="sig-param">*loader_details</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.FileFinder.path_hook" title="Permalink to this definition">¶</a></dt>
<dd><p>A class method which returns a closure for use on <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.path_hooks</span></code></a>.
An instance of <a class="reference internal" href="#importlib.machinery.FileFinder" title="importlib.machinery.FileFinder"><code class="xref py py-class docutils literal notranslate"><span class="pre">FileFinder</span></code></a> is returned by the closure using the
path argument given to the closure directly and <em>loader_details</em>
indirectly.</p>
<p>If the argument to the closure is not an existing directory,
<a class="reference internal" href="exceptions.html#ImportError" title="ImportError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ImportError</span></code></a> is raised.</p>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.machinery.SourceFileLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">SourceFileLoader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourceFileLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.SourceLoader</span></code></a> by
subclassing <a class="reference internal" href="#importlib.abc.FileLoader" title="importlib.abc.FileLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.FileLoader</span></code></a> and providing some concrete
implementations of other methods.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.machinery.SourceFileLoader.name">
<code class="sig-name descname">name</code><a class="headerlink" href="#importlib.machinery.SourceFileLoader.name" title="Permalink to this definition">¶</a></dt>
<dd><p>The name of the module that this loader will handle.</p>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.SourceFileLoader.path">
<code class="sig-name descname">path</code><a class="headerlink" href="#importlib.machinery.SourceFileLoader.path" title="Permalink to this definition">¶</a></dt>
<dd><p>The path to the source file.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourceFileLoader.is_package">
<code class="sig-name descname">is_package</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourceFileLoader.is_package" title="Permalink to this definition">¶</a></dt>
<dd><p>Return <code class="docutils literal notranslate"><span class="pre">True</span></code> if <a class="reference internal" href="#importlib.machinery.SourceFileLoader.path" title="importlib.machinery.SourceFileLoader.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a> appears to be for a package.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourceFileLoader.path_stats">
<code class="sig-name descname">path_stats</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourceFileLoader.path_stats" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader.path_stats" title="importlib.abc.SourceLoader.path_stats"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.SourceLoader.path_stats()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourceFileLoader.set_data">
<code class="sig-name descname">set_data</code><span class="sig-paren">(</span><em class="sig-param">path</em>, <em class="sig-param">data</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourceFileLoader.set_data" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.SourceLoader.set_data" title="importlib.abc.SourceLoader.set_data"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.SourceLoader.set_data()</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourceFileLoader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">name=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourceFileLoader.load_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.load_module()</span></code></a> where
specifying the name of the module to load is optional.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.6: </span>Use <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.exec_module()</span></code></a> instead.</p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.machinery.SourcelessFileLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">SourcelessFileLoader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.FileLoader" title="importlib.abc.FileLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.FileLoader</span></code></a> which can
import bytecode files (i.e. no source code files exist).</p>
<p>Please note that direct use of bytecode files (and thus not source code
files) inhibits your modules from being usable by all Python
implementations or new versions of Python which change the bytecode
format.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.machinery.SourcelessFileLoader.name">
<code class="sig-name descname">name</code><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.name" title="Permalink to this definition">¶</a></dt>
<dd><p>The name of the module the loader will handle.</p>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.SourcelessFileLoader.path">
<code class="sig-name descname">path</code><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.path" title="Permalink to this definition">¶</a></dt>
<dd><p>The path to the bytecode file.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourcelessFileLoader.is_package">
<code class="sig-name descname">is_package</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.is_package" title="Permalink to this definition">¶</a></dt>
<dd><p>Determines if the module is a package based on <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.path" title="importlib.machinery.SourcelessFileLoader.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourcelessFileLoader.get_code">
<code class="sig-name descname">get_code</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.get_code" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns the code object for <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.name" title="importlib.machinery.SourcelessFileLoader.name"><code class="xref py py-attr docutils literal notranslate"><span class="pre">name</span></code></a> created from <a class="reference internal" href="#importlib.machinery.SourcelessFileLoader.path" title="importlib.machinery.SourcelessFileLoader.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourcelessFileLoader.get_source">
<code class="sig-name descname">get_source</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.get_source" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> as bytecode files have no source when this loader is
used.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.SourcelessFileLoader.load_module">
<code class="sig-name descname">load_module</code><span class="sig-paren">(</span><em class="sig-param">name=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.SourcelessFileLoader.load_module" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>Concrete implementation of <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.load_module()</span></code></a> where
specifying the name of the module to load is optional.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.6: </span>Use <a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.exec_module()</span></code></a> instead.</p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.machinery.ExtensionFileLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">ExtensionFileLoader</code><span class="sig-paren">(</span><em class="sig-param">fullname</em>, <em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>A concrete implementation of <a class="reference internal" href="#importlib.abc.ExecutionLoader" title="importlib.abc.ExecutionLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.ExecutionLoader</span></code></a> for
extension modules.</p>
<p>The <em>fullname</em> argument specifies the name of the module the loader is to
support. The <em>path</em> argument is the path to the extension module’s file.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.machinery.ExtensionFileLoader.name">
<code class="sig-name descname">name</code><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.name" title="Permalink to this definition">¶</a></dt>
<dd><p>Name of the module the loader supports.</p>
</dd></dl>

<dl class="attribute">
<dt id="importlib.machinery.ExtensionFileLoader.path">
<code class="sig-name descname">path</code><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.path" title="Permalink to this definition">¶</a></dt>
<dd><p>Path to the extension module.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.create_module">
<code class="sig-name descname">create_module</code><span class="sig-paren">(</span><em class="sig-param">spec</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.create_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Creates the module object from the given specification in accordance
with <span class="target" id="index-19"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0489"><strong>PEP 489</strong></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.5.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.exec_module">
<code class="sig-name descname">exec_module</code><span class="sig-paren">(</span><em class="sig-param">module</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.exec_module" title="Permalink to this definition">¶</a></dt>
<dd><p>Initializes the given module object in accordance with <span class="target" id="index-20"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0489"><strong>PEP 489</strong></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.5.</span></p>
</div>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.is_package">
<code class="sig-name descname">is_package</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.is_package" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <code class="docutils literal notranslate"><span class="pre">True</span></code> if the file path points to a package’s <code class="docutils literal notranslate"><span class="pre">__init__</span></code>
module based on <a class="reference internal" href="#importlib.machinery.EXTENSION_SUFFIXES" title="importlib.machinery.EXTENSION_SUFFIXES"><code class="xref py py-attr docutils literal notranslate"><span class="pre">EXTENSION_SUFFIXES</span></code></a>.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.get_code">
<code class="sig-name descname">get_code</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.get_code" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> as extension modules lack a code object.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.get_source">
<code class="sig-name descname">get_source</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.get_source" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <code class="docutils literal notranslate"><span class="pre">None</span></code> as extension modules do not have source code.</p>
</dd></dl>

<dl class="method">
<dt id="importlib.machinery.ExtensionFileLoader.get_filename">
<code class="sig-name descname">get_filename</code><span class="sig-paren">(</span><em class="sig-param">fullname</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ExtensionFileLoader.get_filename" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns <a class="reference internal" href="#importlib.machinery.ExtensionFileLoader.path" title="importlib.machinery.ExtensionFileLoader.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">path</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

</dd></dl>

<dl class="class">
<dt id="importlib.machinery.ModuleSpec">
<em class="property">class </em><code class="sig-prename descclassname">importlib.machinery.</code><code class="sig-name descname">ModuleSpec</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">loader</em>, <em class="sig-param">*</em>, <em class="sig-param">origin=None</em>, <em class="sig-param">loader_state=None</em>, <em class="sig-param">is_package=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.machinery.ModuleSpec" title="Permalink to this definition">¶</a></dt>
<dd><p>A specification for a module’s import-system-related state.  This is
typically exposed as the module’s <code class="docutils literal notranslate"><span class="pre">__spec__</span></code> attribute.  In the
descriptions below, the names in parentheses give the corresponding
attribute available directly on the module object.
E.g. <code class="docutils literal notranslate"><span class="pre">module.__spec__.origin</span> <span class="pre">==</span> <span class="pre">module.__file__</span></code>.  Note however that
while the <em>values</em> are usually equivalent, they can differ since there is
no synchronization between the two objects.  Thus it is possible to update
the module’s <code class="docutils literal notranslate"><span class="pre">__path__</span></code> at runtime, and this will not be automatically
reflected in <code class="docutils literal notranslate"><span class="pre">__spec__.submodule_search_locations</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.name">
<code class="sig-name descname">name</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.name" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__name__</span></code>)</p>
<p>A string for the fully-qualified name of the module.</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.loader">
<code class="sig-name descname">loader</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.loader" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__loader__</span></code>)</p>
<p>The <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">Loader</span></a> that should be used when loading
the module.  <a class="reference internal" href="../glossary.html#term-finder"><span class="xref std std-term">Finders</span></a> should always set this.</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.origin">
<code class="sig-name descname">origin</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.origin" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__file__</span></code>)</p>
<p>Name of the place from which the module is loaded, e.g. “builtin” for
built-in modules and the filename for modules loaded from source.
Normally “origin” should be set, but it may be <code class="docutils literal notranslate"><span class="pre">None</span></code> (the default)
which indicates it is unspecified (e.g. for namespace packages).</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.submodule_search_locations">
<code class="sig-name descname">submodule_search_locations</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.submodule_search_locations" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__path__</span></code>)</p>
<p>List of strings for where to find submodules, if a package (<code class="docutils literal notranslate"><span class="pre">None</span></code>
otherwise).</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.loader_state">
<code class="sig-name descname">loader_state</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.loader_state" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>Container of extra module-specific data for use during loading (or
<code class="docutils literal notranslate"><span class="pre">None</span></code>).</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.cached">
<code class="sig-name descname">cached</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.cached" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__cached__</span></code>)</p>
<p>String for where the compiled module should be stored (or <code class="docutils literal notranslate"><span class="pre">None</span></code>).</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.parent">
<code class="sig-name descname">parent</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.parent" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>(<code class="docutils literal notranslate"><span class="pre">__package__</span></code>)</p>
<p>(Read-only) The fully-qualified name of the package under which the module
should be loaded as a submodule (or the empty string for top-level modules).
For packages, it is the same as <a class="reference internal" href="../reference/import.html#__name__" title="__name__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__name__</span></code></a>.</p>
<dl class="attribute">
<dt id="importlib.machinery.ModuleSpec.has_location">
<code class="sig-name descname">has_location</code><a class="headerlink" href="#importlib.machinery.ModuleSpec.has_location" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<p>Boolean indicating whether or not the module’s “origin”
attribute refers to a loadable location.</p>
</dd></dl>

</div>
<div class="section" id="module-importlib.util">
<span id="importlib-util-utility-code-for-importers"></span><h2><a class="reference internal" href="#module-importlib.util" title="importlib.util: Utility code for importers"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.util</span></code></a> – Utility code for importers<a class="headerlink" href="#module-importlib.util" title="Permalink to this headline">¶</a></h2>
<p><strong>Source code:</strong> <a class="reference external" href="https://github.com/python/cpython/tree/3.8/Lib/importlib/util.py">Lib/importlib/util.py</a></p>
<hr class="docutils" />
<p>This module contains the various objects that help in the construction of
an <a class="reference internal" href="../glossary.html#term-importer"><span class="xref std std-term">importer</span></a>.</p>
<dl class="attribute">
<dt id="importlib.util.MAGIC_NUMBER">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">MAGIC_NUMBER</code><a class="headerlink" href="#importlib.util.MAGIC_NUMBER" title="Permalink to this definition">¶</a></dt>
<dd><p>The bytes which represent the bytecode version number. If you need help with
loading/writing bytecode then consider <a class="reference internal" href="#importlib.abc.SourceLoader" title="importlib.abc.SourceLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.abc.SourceLoader</span></code></a>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.cache_from_source">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">cache_from_source</code><span class="sig-paren">(</span><em class="sig-param">path</em>, <em class="sig-param">debug_override=None</em>, <em class="sig-param">*</em>, <em class="sig-param">optimization=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.cache_from_source" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the <span class="target" id="index-21"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a>/<span class="target" id="index-22"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0488"><strong>PEP 488</strong></a> path to the byte-compiled file associated
with the source <em>path</em>.  For example, if <em>path</em> is <code class="docutils literal notranslate"><span class="pre">/foo/bar/baz.py</span></code> the return
value would be <code class="docutils literal notranslate"><span class="pre">/foo/bar/__pycache__/baz.cpython-32.pyc</span></code> for Python 3.2.
The <code class="docutils literal notranslate"><span class="pre">cpython-32</span></code> string comes from the current magic tag (see
<code class="xref py py-func docutils literal notranslate"><span class="pre">get_tag()</span></code>; if <code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.implementation.cache_tag</span></code> is not defined then
<a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a> will be raised).</p>
<p>The <em>optimization</em> parameter is used to specify the optimization level of the
bytecode file. An empty string represents no optimization, so
<code class="docutils literal notranslate"><span class="pre">/foo/bar/baz.py</span></code> with an <em>optimization</em> of <code class="docutils literal notranslate"><span class="pre">''</span></code> will result in a
bytecode path of <code class="docutils literal notranslate"><span class="pre">/foo/bar/__pycache__/baz.cpython-32.pyc</span></code>. <code class="docutils literal notranslate"><span class="pre">None</span></code> causes
the interpreter’s optimization level to be used. Any other value’s string
representation is used, so <code class="docutils literal notranslate"><span class="pre">/foo/bar/baz.py</span></code> with an <em>optimization</em> of
<code class="docutils literal notranslate"><span class="pre">2</span></code> will lead to the bytecode path of
<code class="docutils literal notranslate"><span class="pre">/foo/bar/__pycache__/baz.cpython-32.opt-2.pyc</span></code>. The string representation
of <em>optimization</em> can only be alphanumeric, else <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised.</p>
<p>The <em>debug_override</em> parameter is deprecated and can be used to override
the system’s value for <code class="docutils literal notranslate"><span class="pre">__debug__</span></code>. A <code class="docutils literal notranslate"><span class="pre">True</span></code> value is the equivalent of
setting <em>optimization</em> to the empty string. A <code class="docutils literal notranslate"><span class="pre">False</span></code> value is the same as
setting <em>optimization</em> to <code class="docutils literal notranslate"><span class="pre">1</span></code>. If both <em>debug_override</em> an <em>optimization</em>
are not <code class="docutils literal notranslate"><span class="pre">None</span></code> then <a class="reference internal" href="exceptions.html#TypeError" title="TypeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">TypeError</span></code></a> is raised.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.5: </span>The <em>optimization</em> parameter was added and the <em>debug_override</em> parameter
was deprecated.</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.6: </span>Accepts a <a class="reference internal" href="../glossary.html#term-path-like-object"><span class="xref std std-term">path-like object</span></a>.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.source_from_cache">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">source_from_cache</code><span class="sig-paren">(</span><em class="sig-param">path</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.source_from_cache" title="Permalink to this definition">¶</a></dt>
<dd><p>Given the <em>path</em> to a <span class="target" id="index-23"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a> file name, return the associated source code
file path.  For example, if <em>path</em> is
<code class="docutils literal notranslate"><span class="pre">/foo/bar/__pycache__/baz.cpython-32.pyc</span></code> the returned path would be
<code class="docutils literal notranslate"><span class="pre">/foo/bar/baz.py</span></code>.  <em>path</em> need not exist, however if it does not conform
to <span class="target" id="index-24"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-3147"><strong>PEP 3147</strong></a> or <span class="target" id="index-25"></span><a class="pep reference external" href="https://www.python.org/dev/peps/pep-0488"><strong>PEP 488</strong></a> format, a <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised. If
<code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.implementation.cache_tag</span></code> is not defined,
<a class="reference internal" href="exceptions.html#NotImplementedError" title="NotImplementedError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">NotImplementedError</span></code></a> is raised.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.6: </span>Accepts a <a class="reference internal" href="../glossary.html#term-path-like-object"><span class="xref std std-term">path-like object</span></a>.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.decode_source">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">decode_source</code><span class="sig-paren">(</span><em class="sig-param">source_bytes</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.decode_source" title="Permalink to this definition">¶</a></dt>
<dd><p>Decode the given bytes representing source code and return it as a string
with universal newlines (as required by
<a class="reference internal" href="#importlib.abc.InspectLoader.get_source" title="importlib.abc.InspectLoader.get_source"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.InspectLoader.get_source()</span></code></a>).</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.resolve_name">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">resolve_name</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">package</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.resolve_name" title="Permalink to this definition">¶</a></dt>
<dd><p>Resolve a relative module name to an absolute one.</p>
<p>If  <strong>name</strong> has no leading dots, then <strong>name</strong> is simply returned. This
allows for usage such as
<code class="docutils literal notranslate"><span class="pre">importlib.util.resolve_name('sys',</span> <span class="pre">__spec__.parent)</span></code> without doing a
check to see if the <strong>package</strong> argument is needed.</p>
<p><a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised if <strong>name</strong> is a relative module name but
package is a false value (e.g. <code class="docutils literal notranslate"><span class="pre">None</span></code> or the empty string).
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is also raised a relative name would escape its containing
package (e.g. requesting <code class="docutils literal notranslate"><span class="pre">..bacon</span></code> from within the <code class="docutils literal notranslate"><span class="pre">spam</span></code> package).</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.3.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.find_spec">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">find_spec</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">package=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.find_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>Find the <a class="reference internal" href="../glossary.html#term-module-spec"><span class="xref std std-term">spec</span></a> for a module, optionally relative to
the specified <strong>package</strong> name. If the module is in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.modules</span></code></a>,
then <code class="docutils literal notranslate"><span class="pre">sys.modules[name].__spec__</span></code> is returned (unless the spec would be
<code class="docutils literal notranslate"><span class="pre">None</span></code> or is not set, in which case <a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised).
Otherwise a search using <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a> is done. <code class="docutils literal notranslate"><span class="pre">None</span></code> is
returned if no spec is found.</p>
<p>If <strong>name</strong> is for a submodule (contains a dot), the parent module is
automatically imported.</p>
<p><strong>name</strong> and <strong>package</strong> work the same as for <code class="xref py py-func docutils literal notranslate"><span class="pre">import_module()</span></code>.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.7: </span>Raises <a class="reference internal" href="exceptions.html#ModuleNotFoundError" title="ModuleNotFoundError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ModuleNotFoundError</span></code></a> instead of <a class="reference internal" href="exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a> if
<strong>package</strong> is in fact not a package (i.e. lacks a <a class="reference internal" href="../reference/import.html#__path__" title="__path__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__path__</span></code></a>
attribute).</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.module_from_spec">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">module_from_spec</code><span class="sig-paren">(</span><em class="sig-param">spec</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.module_from_spec" title="Permalink to this definition">¶</a></dt>
<dd><p>Create a new module based on <strong>spec</strong> and
<a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">spec.loader.create_module</span></code></a>.</p>
<p>If <a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">spec.loader.create_module</span></code></a>
does not return <code class="docutils literal notranslate"><span class="pre">None</span></code>, then any pre-existing attributes will not be reset.
Also, no <a class="reference internal" href="exceptions.html#AttributeError" title="AttributeError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">AttributeError</span></code></a> will be raised if triggered while accessing
<strong>spec</strong> or setting an attribute on the module.</p>
<p>This function is preferred over using <a class="reference internal" href="types.html#types.ModuleType" title="types.ModuleType"><code class="xref py py-class docutils literal notranslate"><span class="pre">types.ModuleType</span></code></a> to create a
new module as <strong>spec</strong> is used to set as many import-controlled attributes on
the module as possible.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.5.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.module_for_loader">
<code class="sig-prename descclassname">&#64;</code><code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">module_for_loader</code><a class="headerlink" href="#importlib.util.module_for_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>A <a class="reference internal" href="../glossary.html#term-decorator"><span class="xref std std-term">decorator</span></a> for <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.load_module()</span></code></a>
to handle selecting the proper
module object to load with. The decorated method is expected to have a call
signature taking two positional arguments
(e.g. <code class="docutils literal notranslate"><span class="pre">load_module(self,</span> <span class="pre">module)</span></code>) for which the second argument
will be the module <strong>object</strong> to be used by the loader.
Note that the decorator will not work on static methods because of the
assumption of two arguments.</p>
<p>The decorated method will take in the <strong>name</strong> of the module to be loaded
as expected for a <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a>. If the module is not found in
<a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a> then a new one is constructed. Regardless of where the
module came from, <a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a> set to <strong>self</strong> and <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a>
is set based on what <a class="reference internal" href="#importlib.abc.InspectLoader.is_package" title="importlib.abc.InspectLoader.is_package"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.InspectLoader.is_package()</span></code></a> returns
(if available). These attributes are set unconditionally to support
reloading.</p>
<p>If an exception is raised by the decorated method and a module was added to
<a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>, then the module will be removed to prevent a partially
initialized module from being in left in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a>. If the module
was already in <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-data docutils literal notranslate"><span class="pre">sys.modules</span></code></a> then it is left alone.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.3: </span><a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a> and <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a> are automatically set
(when possible).</p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Set <a class="reference internal" href="../reference/import.html#__name__" title="__name__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__name__</span></code></a>, <a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a> <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a>
unconditionally to support reloading.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>The import machinery now directly performs all the functionality
provided by this function.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.set_loader">
<code class="sig-prename descclassname">&#64;</code><code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">set_loader</code><a class="headerlink" href="#importlib.util.set_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>A <a class="reference internal" href="../glossary.html#term-decorator"><span class="xref std std-term">decorator</span></a> for <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.load_module()</span></code></a>
to set the <a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a>
attribute on the returned module. If the attribute is already set the
decorator does nothing. It is assumed that the first positional argument to
the wrapped method (i.e. <code class="docutils literal notranslate"><span class="pre">self</span></code>) is what <a class="reference internal" href="../reference/import.html#__loader__" title="__loader__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__loader__</span></code></a> should be set
to.</p>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.4: </span>Set <code class="docutils literal notranslate"><span class="pre">__loader__</span></code> if set to <code class="docutils literal notranslate"><span class="pre">None</span></code>, as if the attribute does not
exist.</p>
</div>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>The import machinery takes care of this automatically.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.set_package">
<code class="sig-prename descclassname">&#64;</code><code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">set_package</code><a class="headerlink" href="#importlib.util.set_package" title="Permalink to this definition">¶</a></dt>
<dd><p>A <a class="reference internal" href="../glossary.html#term-decorator"><span class="xref std std-term">decorator</span></a> for <a class="reference internal" href="#importlib.abc.Loader.load_module" title="importlib.abc.Loader.load_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">importlib.abc.Loader.load_module()</span></code></a> to set the
<a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a> attribute on the returned module. If <a class="reference internal" href="../reference/import.html#__package__" title="__package__"><code class="xref py py-attr docutils literal notranslate"><span class="pre">__package__</span></code></a>
is set and has a value other than <code class="docutils literal notranslate"><span class="pre">None</span></code> it will not be changed.</p>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 3.4: </span>The import machinery takes care of this automatically.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.spec_from_loader">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">spec_from_loader</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">loader</em>, <em class="sig-param">*</em>, <em class="sig-param">origin=None</em>, <em class="sig-param">is_package=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.spec_from_loader" title="Permalink to this definition">¶</a></dt>
<dd><p>A factory function for creating a <code class="xref py py-class docutils literal notranslate"><span class="pre">ModuleSpec</span></code> instance based
on a loader.  The parameters have the same meaning as they do for
ModuleSpec.  The function uses available <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a> APIs, such as
<code class="xref py py-meth docutils literal notranslate"><span class="pre">InspectLoader.is_package()</span></code>, to fill in any missing
information on the spec.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.spec_from_file_location">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">spec_from_file_location</code><span class="sig-paren">(</span><em class="sig-param">name</em>, <em class="sig-param">location</em>, <em class="sig-param">*</em>, <em class="sig-param">loader=None</em>, <em class="sig-param">submodule_search_locations=None</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.spec_from_file_location" title="Permalink to this definition">¶</a></dt>
<dd><p>A factory function for creating a <code class="xref py py-class docutils literal notranslate"><span class="pre">ModuleSpec</span></code> instance based
on the path to a file.  Missing information will be filled in on the
spec by making use of loader APIs and by the implication that the
module will be file-based.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.4.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.6: </span>Accepts a <a class="reference internal" href="../glossary.html#term-path-like-object"><span class="xref std std-term">path-like object</span></a>.</p>
</div>
</dd></dl>

<dl class="function">
<dt id="importlib.util.source_hash">
<code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">source_hash</code><span class="sig-paren">(</span><em class="sig-param">source_bytes</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.source_hash" title="Permalink to this definition">¶</a></dt>
<dd><p>Return the hash of <em>source_bytes</em> as bytes. A hash-based <code class="docutils literal notranslate"><span class="pre">.pyc</span></code> file embeds
the <a class="reference internal" href="#importlib.util.source_hash" title="importlib.util.source_hash"><code class="xref py py-func docutils literal notranslate"><span class="pre">source_hash()</span></code></a> of the corresponding source file’s contents in its
header.</p>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.7.</span></p>
</div>
</dd></dl>

<dl class="class">
<dt id="importlib.util.LazyLoader">
<em class="property">class </em><code class="sig-prename descclassname">importlib.util.</code><code class="sig-name descname">LazyLoader</code><span class="sig-paren">(</span><em class="sig-param">loader</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.LazyLoader" title="Permalink to this definition">¶</a></dt>
<dd><p>A class which postpones the execution of the loader of a module until the
module has an attribute accessed.</p>
<p>This class <strong>only</strong> works with loaders that define
<a class="reference internal" href="#importlib.abc.Loader.exec_module" title="importlib.abc.Loader.exec_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">exec_module()</span></code></a> as control over what module type
is used for the module is required. For those same reasons, the loader’s
<a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code></a> method must return <code class="docutils literal notranslate"><span class="pre">None</span></code> or a
type for which its <code class="docutils literal notranslate"><span class="pre">__class__</span></code> attribute can be mutated along with not
using <a class="reference internal" href="../glossary.html#term-slots"><span class="xref std std-term">slots</span></a>. Finally, modules which substitute the object
placed into <a class="reference internal" href="sys.html#sys.modules" title="sys.modules"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.modules</span></code></a> will not work as there is no way to properly
replace the module references throughout the interpreter safely;
<a class="reference internal" href="exceptions.html#ValueError" title="ValueError"><code class="xref py py-exc docutils literal notranslate"><span class="pre">ValueError</span></code></a> is raised if such a substitution is detected.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>For projects where startup time is critical, this class allows for
potentially minimizing the cost of loading a module if it is never used.
For projects where startup time is not essential then use of this class is
<strong>heavily</strong> discouraged due to error messages created during loading being
postponed and thus occurring out of context.</p>
</div>
<div class="versionadded">
<p><span class="versionmodified added">New in version 3.5.</span></p>
</div>
<div class="versionchanged">
<p><span class="versionmodified changed">Changed in version 3.6: </span>Began calling <a class="reference internal" href="#importlib.abc.Loader.create_module" title="importlib.abc.Loader.create_module"><code class="xref py py-meth docutils literal notranslate"><span class="pre">create_module()</span></code></a>, removing the
compatibility warning for <a class="reference internal" href="#importlib.machinery.BuiltinImporter" title="importlib.machinery.BuiltinImporter"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.machinery.BuiltinImporter</span></code></a> and
<a class="reference internal" href="#importlib.machinery.ExtensionFileLoader" title="importlib.machinery.ExtensionFileLoader"><code class="xref py py-class docutils literal notranslate"><span class="pre">importlib.machinery.ExtensionFileLoader</span></code></a>.</p>
</div>
<dl class="method">
<dt id="importlib.util.LazyLoader.factory">
<em class="property">classmethod </em><code class="sig-name descname">factory</code><span class="sig-paren">(</span><em class="sig-param">loader</em><span class="sig-paren">)</span><a class="headerlink" href="#importlib.util.LazyLoader.factory" title="Permalink to this definition">¶</a></dt>
<dd><p>A static method which returns a callable that creates a lazy loader. This
is meant to be used in situations where the loader is passed by class
instead of by instance.</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="n">suffixes</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">SOURCE_SUFFIXES</span>
<span class="n">loader</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">SourceFileLoader</span>
<span class="n">lazy_loader</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">LazyLoader</span><span class="o">.</span><span class="n">factory</span><span class="p">(</span><span class="n">loader</span><span class="p">)</span>
<span class="n">finder</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">FileFinder</span><span class="p">(</span><span class="n">path</span><span class="p">,</span> <span class="p">(</span><span class="n">lazy_loader</span><span class="p">,</span> <span class="n">suffixes</span><span class="p">))</span>
</pre></div>
</div>
</dd></dl>

</dd></dl>

</div>
<div class="section" id="examples">
<span id="importlib-examples"></span><h2>Examples<a class="headerlink" href="#examples" title="Permalink to this headline">¶</a></h2>
<div class="section" id="importing-programmatically">
<h3>Importing programmatically<a class="headerlink" href="#importing-programmatically" title="Permalink to this headline">¶</a></h3>
<p>To programmatically import a module, use <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.import_module()</span></code></a>.</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">importlib</span>

<span class="n">itertools</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">import_module</span><span class="p">(</span><span class="s1">&#39;itertools&#39;</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="checking-if-a-module-can-be-imported">
<h3>Checking if a module can be imported<a class="headerlink" href="#checking-if-a-module-can-be-imported" title="Permalink to this headline">¶</a></h3>
<p>If you need to find out if a module can be imported without actually doing the
import, then you should use <a class="reference internal" href="#importlib.util.find_spec" title="importlib.util.find_spec"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.util.find_spec()</span></code></a>.</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">importlib.util</span>
<span class="kn">import</span> <span class="nn">sys</span>

<span class="c1"># For illustrative purposes.</span>
<span class="n">name</span> <span class="o">=</span> <span class="s1">&#39;itertools&#39;</span>

<span class="k">if</span> <span class="n">name</span> <span class="ow">in</span> <span class="n">sys</span><span class="o">.</span><span class="n">modules</span><span class="p">:</span>
    <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">name</span><span class="si">!r}</span><span class="s2"> already in sys.modules&quot;</span><span class="p">)</span>
<span class="k">elif</span> <span class="p">(</span><span class="n">spec</span> <span class="o">:=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">find_spec</span><span class="p">(</span><span class="n">name</span><span class="p">))</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
    <span class="c1"># If you chose to perform the actual import ...</span>
    <span class="n">module</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">module_from_spec</span><span class="p">(</span><span class="n">spec</span><span class="p">)</span>
    <span class="n">sys</span><span class="o">.</span><span class="n">modules</span><span class="p">[</span><span class="n">name</span><span class="p">]</span> <span class="o">=</span> <span class="n">module</span>
    <span class="n">spec</span><span class="o">.</span><span class="n">loader</span><span class="o">.</span><span class="n">exec_module</span><span class="p">(</span><span class="n">module</span><span class="p">)</span>
    <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;</span><span class="si">{</span><span class="n">name</span><span class="si">!r}</span><span class="s2"> has been imported&quot;</span><span class="p">)</span>
<span class="k">else</span><span class="p">:</span>
    <span class="nb">print</span><span class="p">(</span><span class="sa">f</span><span class="s2">&quot;can&#39;t find the </span><span class="si">{</span><span class="n">name</span><span class="si">!r}</span><span class="s2"> module&quot;</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="importing-a-source-file-directly">
<h3>Importing a source file directly<a class="headerlink" href="#importing-a-source-file-directly" title="Permalink to this headline">¶</a></h3>
<p>To import a Python source file directly, use the following recipe
(Python 3.5 and newer only):</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">importlib.util</span>
<span class="kn">import</span> <span class="nn">sys</span>

<span class="c1"># For illustrative purposes.</span>
<span class="kn">import</span> <span class="nn">tokenize</span>
<span class="n">file_path</span> <span class="o">=</span> <span class="n">tokenize</span><span class="o">.</span><span class="vm">__file__</span>
<span class="n">module_name</span> <span class="o">=</span> <span class="n">tokenize</span><span class="o">.</span><span class="vm">__name__</span>

<span class="n">spec</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">spec_from_file_location</span><span class="p">(</span><span class="n">module_name</span><span class="p">,</span> <span class="n">file_path</span><span class="p">)</span>
<span class="n">module</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">module_from_spec</span><span class="p">(</span><span class="n">spec</span><span class="p">)</span>
<span class="n">sys</span><span class="o">.</span><span class="n">modules</span><span class="p">[</span><span class="n">module_name</span><span class="p">]</span> <span class="o">=</span> <span class="n">module</span>
<span class="n">spec</span><span class="o">.</span><span class="n">loader</span><span class="o">.</span><span class="n">exec_module</span><span class="p">(</span><span class="n">module</span><span class="p">)</span>
</pre></div>
</div>
</div>
<div class="section" id="setting-up-an-importer">
<h3>Setting up an importer<a class="headerlink" href="#setting-up-an-importer" title="Permalink to this headline">¶</a></h3>
<p>For deep customizations of import, you typically want to implement an
<a class="reference internal" href="../glossary.html#term-importer"><span class="xref std std-term">importer</span></a>. This means managing both the <a class="reference internal" href="../glossary.html#term-finder"><span class="xref std std-term">finder</span></a> and <a class="reference internal" href="../glossary.html#term-loader"><span class="xref std std-term">loader</span></a>
side of things. For finders there are two flavours to choose from depending on
your needs: a <a class="reference internal" href="../glossary.html#term-meta-path-finder"><span class="xref std std-term">meta path finder</span></a> or a <a class="reference internal" href="../glossary.html#term-path-entry-finder"><span class="xref std std-term">path entry finder</span></a>. The
former is what you would put on <a class="reference internal" href="sys.html#sys.meta_path" title="sys.meta_path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.meta_path</span></code></a> while the latter is what
you create using a <a class="reference internal" href="../glossary.html#term-path-entry-hook"><span class="xref std std-term">path entry hook</span></a> on <a class="reference internal" href="sys.html#sys.path_hooks" title="sys.path_hooks"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.path_hooks</span></code></a> which works
with <a class="reference internal" href="sys.html#sys.path" title="sys.path"><code class="xref py py-attr docutils literal notranslate"><span class="pre">sys.path</span></code></a> entries to potentially create a finder. This example will
show you how to register your own importers so that import will use them (for
creating an importer for yourself, read the documentation for the appropriate
classes defined within this package):</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">importlib.machinery</span>
<span class="kn">import</span> <span class="nn">sys</span>

<span class="c1"># For illustrative purposes only.</span>
<span class="n">SpamMetaPathFinder</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">PathFinder</span>
<span class="n">SpamPathEntryFinder</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">FileFinder</span>
<span class="n">loader_details</span> <span class="o">=</span> <span class="p">(</span><span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">SourceFileLoader</span><span class="p">,</span>
                  <span class="n">importlib</span><span class="o">.</span><span class="n">machinery</span><span class="o">.</span><span class="n">SOURCE_SUFFIXES</span><span class="p">)</span>

<span class="c1"># Setting up a meta path finder.</span>
<span class="c1"># Make sure to put the finder in the proper location in the list in terms of</span>
<span class="c1"># priority.</span>
<span class="n">sys</span><span class="o">.</span><span class="n">meta_path</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">SpamMetaPathFinder</span><span class="p">)</span>

<span class="c1"># Setting up a path entry finder.</span>
<span class="c1"># Make sure to put the path hook in the proper location in the list in terms</span>
<span class="c1"># of priority.</span>
<span class="n">sys</span><span class="o">.</span><span class="n">path_hooks</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">SpamPathEntryFinder</span><span class="o">.</span><span class="n">path_hook</span><span class="p">(</span><span class="n">loader_details</span><span class="p">))</span>
</pre></div>
</div>
</div>
<div class="section" id="approximating-importlib-import-module">
<h3>Approximating <a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.import_module()</span></code></a><a class="headerlink" href="#approximating-importlib-import-module" title="Permalink to this headline">¶</a></h3>
<p>Import itself is implemented in Python code, making it possible to
expose most of the import machinery through importlib. The following
helps illustrate the various APIs that importlib exposes by providing an
approximate implementation of
<a class="reference internal" href="#importlib.import_module" title="importlib.import_module"><code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.import_module()</span></code></a> (Python 3.4 and newer for the importlib usage,
Python 3.6 and newer for other parts of the code).</p>
<div class="highlight-python3 notranslate"><div class="highlight"><pre><span></span><span class="kn">import</span> <span class="nn">importlib.util</span>
<span class="kn">import</span> <span class="nn">sys</span>

<span class="k">def</span> <span class="nf">import_module</span><span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">package</span><span class="o">=</span><span class="kc">None</span><span class="p">):</span>
    <span class="sd">&quot;&quot;&quot;An approximate implementation of import.&quot;&quot;&quot;</span>
    <span class="n">absolute_name</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">resolve_name</span><span class="p">(</span><span class="n">name</span><span class="p">,</span> <span class="n">package</span><span class="p">)</span>
    <span class="k">try</span><span class="p">:</span>
        <span class="k">return</span> <span class="n">sys</span><span class="o">.</span><span class="n">modules</span><span class="p">[</span><span class="n">absolute_name</span><span class="p">]</span>
    <span class="k">except</span> <span class="ne">KeyError</span><span class="p">:</span>
        <span class="k">pass</span>

    <span class="n">path</span> <span class="o">=</span> <span class="kc">None</span>
    <span class="k">if</span> <span class="s1">&#39;.&#39;</span> <span class="ow">in</span> <span class="n">absolute_name</span><span class="p">:</span>
        <span class="n">parent_name</span><span class="p">,</span> <span class="n">_</span><span class="p">,</span> <span class="n">child_name</span> <span class="o">=</span> <span class="n">absolute_name</span><span class="o">.</span><span class="n">rpartition</span><span class="p">(</span><span class="s1">&#39;.&#39;</span><span class="p">)</span>
        <span class="n">parent_module</span> <span class="o">=</span> <span class="n">import_module</span><span class="p">(</span><span class="n">parent_name</span><span class="p">)</span>
        <span class="n">path</span> <span class="o">=</span> <span class="n">parent_module</span><span class="o">.</span><span class="n">__spec__</span><span class="o">.</span><span class="n">submodule_search_locations</span>
    <span class="k">for</span> <span class="n">finder</span> <span class="ow">in</span> <span class="n">sys</span><span class="o">.</span><span class="n">meta_path</span><span class="p">:</span>
        <span class="n">spec</span> <span class="o">=</span> <span class="n">finder</span><span class="o">.</span><span class="n">find_spec</span><span class="p">(</span><span class="n">absolute_name</span><span class="p">,</span> <span class="n">path</span><span class="p">)</span>
        <span class="k">if</span> <span class="n">spec</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
            <span class="k">break</span>
    <span class="k">else</span><span class="p">:</span>
        <span class="n">msg</span> <span class="o">=</span> <span class="sa">f</span><span class="s1">&#39;No module named </span><span class="si">{</span><span class="n">absolute_name</span><span class="si">!r}</span><span class="s1">&#39;</span>
        <span class="k">raise</span> <span class="ne">ModuleNotFoundError</span><span class="p">(</span><span class="n">msg</span><span class="p">,</span> <span class="n">name</span><span class="o">=</span><span class="n">absolute_name</span><span class="p">)</span>
    <span class="n">module</span> <span class="o">=</span> <span class="n">importlib</span><span class="o">.</span><span class="n">util</span><span class="o">.</span><span class="n">module_from_spec</span><span class="p">(</span><span class="n">spec</span><span class="p">)</span>
    <span class="n">sys</span><span class="o">.</span><span class="n">modules</span><span class="p">[</span><span class="n">absolute_name</span><span class="p">]</span> <span class="o">=</span> <span class="n">module</span>
    <span class="n">spec</span><span class="o">.</span><span class="n">loader</span><span class="o">.</span><span class="n">exec_module</span><span class="p">(</span><span class="n">module</span><span class="p">)</span>
    <span class="k">if</span> <span class="n">path</span> <span class="ow">is</span> <span class="ow">not</span> <span class="kc">None</span><span class="p">:</span>
        <span class="nb">setattr</span><span class="p">(</span><span class="n">parent_module</span><span class="p">,</span> <span class="n">child_name</span><span class="p">,</span> <span class="n">module</span><span class="p">)</span>
    <span class="k">return</span> <span class="n">module</span>
</pre></div>
</div>
</div>
</div>
</div>


          </div>
        </div>
      </div>
      <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
        <div class="sphinxsidebarwrapper">
  <h3><a href="../contents.html">Table of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib</span></code> — The implementation of <code class="xref std std-keyword docutils literal notranslate"><span class="pre">import</span></code></a><ul>
<li><a class="reference internal" href="#introduction">Introduction</a></li>
<li><a class="reference internal" href="#functions">Functions</a></li>
<li><a class="reference internal" href="#module-importlib.abc"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.abc</span></code> – Abstract base classes related to import</a></li>
<li><a class="reference internal" href="#module-importlib.resources"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.resources</span></code> – Resources</a></li>
<li><a class="reference internal" href="#module-importlib.machinery"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.machinery</span></code> – Importers and path hooks</a></li>
<li><a class="reference internal" href="#module-importlib.util"><code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.util</span></code> – Utility code for importers</a></li>
<li><a class="reference internal" href="#examples">Examples</a><ul>
<li><a class="reference internal" href="#importing-programmatically">Importing programmatically</a></li>
<li><a class="reference internal" href="#checking-if-a-module-can-be-imported">Checking if a module can be imported</a></li>
<li><a class="reference internal" href="#importing-a-source-file-directly">Importing a source file directly</a></li>
<li><a class="reference internal" href="#setting-up-an-importer">Setting up an importer</a></li>
<li><a class="reference internal" href="#approximating-importlib-import-module">Approximating <code class="xref py py-func docutils literal notranslate"><span class="pre">importlib.import_module()</span></code></a></li>
</ul>
</li>
</ul>
</li>
</ul>

  <h4>Previous topic</h4>
  <p class="topless"><a href="runpy.html"
                        title="previous chapter"><code class="xref py py-mod docutils literal notranslate"><span class="pre">runpy</span></code> — Locating and executing Python modules</a></p>
  <h4>Next topic</h4>
  <p class="topless"><a href="importlib.metadata.html"
                        title="next chapter">Using <code class="xref py py-mod docutils literal notranslate"><span class="pre">importlib.metadata</span></code></a></p>
  <div role="note" aria-label="source link">
    <h3>This Page</h3>
    <ul class="this-page-menu">
      <li><a href="../bugs.html">Report a Bug</a></li>
      <li>
        <a href="https://github.com/python/cpython/blob/3.8/Doc/library/importlib.rst"
            rel="nofollow">Show Source
        </a>
      </li>
    </ul>
  </div>
        </div>
      </div>
      <div class="clearer"></div>
    </div>  
    <div class="related" role="navigation" aria-label="related navigation">
      <h3>Navigation</h3>
      <ul>
        <li class="right" style="margin-right: 10px">
          <a href="../genindex.html" title="General Index"
             >index</a></li>
        <li class="right" >
          <a href="../py-modindex.html" title="Python Module Index"
             >modules</a> |</li>
        <li class="right" >
          <a href="importlib.metadata.html" title="Using importlib.metadata"
             >next</a> |</li>
        <li class="right" >
          <a href="runpy.html" title="runpy — Locating and executing Python modules"
             >previous</a> |</li>

          <li><img src="../_static/py.svg" alt="python logo" style="vertical-align: middle; margin-top: -1px"/></li>
          <li><a href="https://www.python.org/">Python</a> &#187;</li>
          <li class="switchers">
            <div class="language_switcher_placeholder"></div>
            <div class="version_switcher_placeholder"></div>
          </li>
          <li>
              
          </li>
    <li id="cpython-language-and-version">
      <a href="../index.html">3.8.13 Documentation</a> &#187;
    </li>

          <li class="nav-item nav-item-1"><a href="index.html" >The Python Standard Library</a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="modules.html" >Importing Modules</a> &#187;</li>
                <li class="right">
                    

    <div class="inline-search" role="search">
        <form class="inline-search" action="../search.html" method="get">
          <input placeholder="Quick search" aria-label="Quick search" type="text" name="q" />
          <input type="submit" value="Go" />
          <input type="hidden" name="check_keywords" value="yes" />
          <input type="hidden" name="area" value="default" />
        </form>
    </div>
                     |
                </li>
            
      </ul>
    </div>  
    <div class="footer">
    &copy; <a href="../copyright.html">Copyright</a> 2001-2022, Python Software Foundation.
    <br />
    This page is licensed under the Python Software Foundation License Version 2.
    <br />
    Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License.
    <br />
    
    <br />

    The Python Software Foundation is a non-profit corporation.
<a href="https://www.python.org/psf/donations/">Please donate.</a>
<br />
    <br />

    Last updated on Mar 17, 2022.
    <a href="https://docs.python.org/3/bugs.html">Found a bug</a>?
    <br />

    Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 2.4.4.
    </div>

  </body>
</html>